Tag Archives: irish archaeology


There is one thing that I always wondered about fulachta fiadh: why were so many of them built in waterlogged acidic soil, near peat bogs? According to professor Aidan O’Sullivan “fulachta are often found in waterlogged soils by lakes, streams, fens, etc and often close to the edge of a bog. At Killoran fulachta were overwhelmingly located in glacial till at the edges of the bogs”. However according to many other sources, there are actually quite a few fulactha which were set in bogs. For instance a lot of the c.80 burnt mounds on Clare Island seem to be set on bog. 
Every single potential use of fulachta fiadh I have discussed so far would not have been possible if the fulacht fiadh trough was cut into a waterlogged acidic soil. Unless the trough was made absolutely watertight. Which most of them weren’t. Here are two examples. Look at the gaps between the planks in the first one. And the second one is made from roundwood, impossible to make watertight.

Any hole dug in an waterlogged acidic soil would soon fill with acidic water. If the pit was dug in the peat draining area at the edge of the bog, it would soon fill with peat draining water. Whatever the source of the acidic water, the acid in the water would prevent acorns from leaching, would make horrible tasting beer, would make salt extraction through evaporation impossible… 
So why were so many fulachta fiadh built in waterlogged acidic soils and on the edges of bogs? To answer that question we need to understand what peat bogs are.
Bogs are rain fed (ombrotrophic). They need poorly-drained areas, a climate where precipitation exceeds evaporation, and a nutrient-poor environment that favors peat mosses in their ecologic competition against higher plants. Growth of higher plants is also curbed by peat mosses themselves because they bind available nutrients and render the bog water acidic. The acidity comes from the so called low-molecular-weight organic acids (LMWOAs): Formic, acetic, pyruvic, oxalic, malonic, and succinic acids. The amount of these acids in bog water is so high that the pH of bog water is 3-4. This is really acidic indeed. If this bog water is then exposed to the sunshine, it will get even more acidic. 

The article “Photoformation of low-molecular-weight organic acids from brown water dissolved organic matter” by Brinkmann T1, Hörsch P, Sartorius D, Frimmel FH we read:

This work describes the effects of simulated solar UV light on the bulk properties of dissolved organic matter (DOM) of bog lake water and on the formation of low-molecular-weight organic acids (LMWOAs). By means of size-exclusion chromatography it was shown that the more hydrophilic moieties of the DOM were preferentially photodegraded while the more hydrophobic ones remained relatively unaffected or were even formed. The combined photochemical-biological degradation proved to be more important than the pure photochemical mineralization. Formic, acetic, pyruvic, oxalic, malonic, and succinic acids were identified as important degradation products. Their contribution to the dissolved organic carbon increased from 0.31% before to 6.4% after 24 h irradiation. About 33% of the bioavailable photoproducts of DOM were comprised of these LMWOAs.

Translated into plain English, solar radiation will degrade organic matter found in bog water and form more low-molecular-weight organic acids (LMWOAs), making the bog water even more acidic. How much more acidic? Not sure what the final pH of the bog water exposed to the sunshine is. But it is definitely low enough to serve as a very good pickling solution. 

Pickling is the process of preserving or expanding the lifespan of food by immersing in pickling brine (salty and acidic liquid). If the food contains sufficient moisture, a pickling brine may be produced simply by adding dry salt which draws water out of the food creating salty liquid. Natural fermentation at room temperature, by lactic acid bacteria, produces the required acidity creating salty and acidic liquid – pickling brine. If the food does not contain sufficient moisture, pickling can also be achieved by immersion of food in some salty acidic liquid, such as mixture of salty water and vinegar. If you want your pickling to be successful, the pH of the pickling brine has to be 4.6 or lower, which is sufficient to kill most bacteria.  The pickling procedure will typically affect both food’s texture and flavor but it will preserve otherwise easily perishable food for months or longer. Foods that can be pickled include meats, fruits, eggs, vegetables and milk products like cheese.

Now bog water has a pH of 3-4 before solar irradiation. Well below the required acidity of pickling solutions. For those who don’t know much about pH scale, here is a quick overview. The pH scale measures how acidic or basic a substance is. The pH scale ranges from 0 to 14. A pH of 7 is neutral. A pH less than 7 is acidic and more than 7 is caustic. The scale is not linear but logarithmic. This means that liquid with pH 3 is 10 time more acidic than the liquid with pH 4…

So bog water is 10 time more acidic than what is at minimum required from a pickling solution in order to kill all the harmful bacteria in the food. 

Yes but what does pickling has to do with bog water? Who would use bog water for pickling? Well as it turns out a lot of people. And some of them could have been the Bronze Age Irish builders of fulachta fiadh

As I already said in my post “Fulacht fiadh – meat and fish curing facility”, the ancient Irish probably used both salt and smoke curing of meat and fish as a means of preserving it long term. But there is another way Ancient Irish could have preserved food long term without need for salting or smoking. 

They could have buried it into the peat bog.  
This is bog butter:
Bog butter” refers to an ancient waxy substance found buried in peat bogs, particularly in Great Britain and in Ireland. 
In the article entitled “Mysteries of bog butter uncovered” published in the magazine Nature in 2004, we can read that the research by Richard Evershed and his colleagues from the University of Bristol has proven that what is commonly known as the ‘bog butter‘ is the remains of both dairy products and meat encased in the peat.
Those who live in the countryside of Ireland and Scotland and dig up chunks of peat for fuel have long been familiar with bog butter. While gathering the compressed plant matter, which can be burned in fires, diggers occasionally slice into a white substance with the appearance and texture of paraffin wax. This is thought to be the remains of food once buried in the bog to preserve it. Waterlogged peat is cool and contains very little oxygen, so it can be used as a primitive kind of fridge. The question is what type of food was buried in the peat. Local lore sometimes says that the waxy stuff is literally the remains of butter. For example, the seventeenth-century English writer Samuel Butler remarked in one of his famous poems that butter in Ireland “was seven years buried in a bog”. But there could be an alternative source for the waxy material: dead animals. In the eighteenth century, French chemists discovered that human corpses often contain adipocere, a substance also known as ‘grave-wax’. So bog butter could be the remains of carcasses rather than dairy products.

To find out, Evershed and his colleagues took a close look at the fatty acids in bog butter. The chains of hydrocarbons in these molecules differ between those derived from dairy and those from meat. They looked at nine samples of bog butter provided by the National Museum of Scotland, some of which are 2000 years old. They reported that six of the bog butter samples come from dairy products, and three are from animal fat (carcasses). So ancient Scots (read here Irish as the term Scot actually means Irish) clearly used the peat to store both types of food.
In the article “Underwater storage techniques preserved meat for early hunters” by Sally Pobojewski we can read about the experiments performed by Daniel C. Fisher, professor of geological and biological sciences at the University of Michigan and the curator of the Museum of Paleontology, who proved that burying meat in the peat bog will perfectly preserve it for two years.  
From autumn to mid-winter of 1989, Fisher anchored legs of lamb and venison on the bottom of a shallow, open-peat water pond and buried other meat sections in a nearby peat bog. Caches were left in place for up to two years and checked periodically for decomposition. The meat remained essentially fresh for most of the first winter. By spring, progressive discoloration had developed on the outside, but interior tissue looked and smelled reasonably fresh. The combination of cold water temperature and increased acidity in the meat produced by pond bacteria called lactobacilli, which can survive without oxygen, made the meat unpalatable to other bacteria that normally decompose dead tissue, according to Fisher. Laboratory analyses of meat retrieved from the pond and bog in April 1992 showed no significant pathogens and bacterial counts were comparable to levels found in control samples Fisher stored in his home freezer.
So our hunters from the fianna hunting teams could have used the same technique to preserve the meat for the winter. They would bring the animals they have killed to their camp. They would take whatever they wanted to eat on the day, probably internal organs, head and such bits as they are the most perishable. They would cook this as a stew in a pot (not in fulacht fiadh trough 🙂 ). They would maybe even roast some of the animals on a spit over a cooking pit (cooking procedure described in the Irish histories as “cooking using fulacht fiadh”). They would then cut the animal into manageable bits and would place these bits in deep peat bog pits full of acidic peat water, located at the edge of the camp. Or they would bury the meat pieces in deep peat trenches. The meat could then be taken out of the peat storage when needed and either salted and smoked or cooked or sold. 
Professor Fisher suggests that: “Underwater caching turns out to be a simple and effective way to store meat for long periods. Fossils preserved at ancient cache sites suggest it was an important and common part of the winter-to-spring subsistence strategy of Ice Age hunters“. 
And we know from the archaeological evidence that this way of preserving meat and fat was as common in Ancient Ireland and Scotland too. 
This article “Carbohydrate polymers in food preservation: an integrated view of the Maillard reaction with special reference to discoveries of preserved foods in Sphagnum-dominated peat bogs” explores possible use of peat in modern food preservation. It mentions that so far “…biodegradable materials that have been found preserved in peat, including carcasses of domestic animals, loaves of bread, dried fruits, berries, and kegs of butter or cheese…
The article entitled “Peat moss, an old Viking standby, could revolutionize the food-storage industry” says that” Researchers are looking at an old Viking trick–peat moss–as a way of preserving foods and saving millions of dollars per year in refrigeration and transport costs. 
Scandinavian freshwater fishermen traditionally used peat bogs to preserve their catches until they could pick them up on their way out of the mountains. Fish buried in peat moss or treated with a moss extract stayed fresh weeks longer than untreated fish. And we all know how perishable fish is. 

Dr. Terence Painter, professor emeritus at Norwegian University of Science and Technology in Trondheim who researched preservative abilities of peat says that it can be used for long term preservation of highly perishable food stufs. And they have proven that it is not a lack of oxygen or the presence of a chemical called tannin acting as a preservative which is preventing decay.

Painter and his associates, Yngve Boersheim and Bjoern Christensen, isolated a complex sugar in sphagnum moss, which forms peat bogs after hundreds of years. They set out to prove that the sugar, which they have named sphagnum, was the real preservative in a variety of tests in a government-funded study.

In other tests, the researchers treated 3/4-inch-long zebra fish with peat or extract and left others untreated. After two weeks, the treated fish were fine, while the untreated ones had virtually vanished due to decay.

In a demonstration for the Norwegian state radio network NRK, Christensen opened a plastic container in which a zebra fish had been stored on peat for two years. It was intact and smelled fine. This is incredible considering that fish will start smelling in 2 days unless it was frozen straight after it was caught. 

Fish isn’t the only food that may be preserved. Painter said his team has had success with apples, carrots, radishes and other vegetables. Norwegians had a tradition of storing their root plants, such as carrots and turnips, in peat bogs to preserve them.

The researchers have received a Norwegian government grant to start a pilot project testing commercial applications. Painter said it is not clear when the first commercial uses could begin.
This is very very interesting. As I already wrote in my post “Fulacht fiadh – a cooking pit?“:
“The cooking hypothesis is rendered even less convincing by the near absolute lack of animal bone or plant material within the troughs. Proponents of this hypothesis have argued that the lack of animal material is likely due to preferential decay associated with elevated soil acidity, which is a key feature of burnt mound sites, of which many are located on marshy uplands…”  
Now in these marshy areas a pit dug into the ground would quickly fill with water. Acidic marshy water. If the pit is dug at the edge of the peat bog, the water would also contain peat water draining from the bog. If your fulacht is located near the bog but not in the bog drain area, you can dig a hole in the bog, get bog water from it and transfer it using pots. Or you can dig some wet peat, and dissolve it in already acidic marshy water filling your fulacth trough. The resulting peat water is exactly what you need for preserving meat and fish. All you would need to do to preserve your meat or fish would be to dunk it into the pit full of peat water and keep doing this until the pit is almost full. 
You could even salt the meat and fish first before you dunk it into the pit, but you don’t have to. Once you fill the pit, you would then put some logs on top of it all to press the pit content down so that it stays submerged. You would then cover the pit with planks or thick branches (roundwood) and then with a thick layer of peat to thermally insulate it and that’s about it. O yes, you would also need to mark the spot where the pit is, so that you don’t accidentally step into it. 🙂
Once the meat and fish was removed from the pit, there would be no trace left of it to be found by archaeologists today. Except if the meat and fish was for whatever reason forgotten and never taken out. In which case, today, 3000 years later, archaeologists would just find a lump of “bog butter”…
This means that the location of many fulachta fiadh in marshy waterlogged areas near bogs suddenly begins to make sense. Was one of the reason why the hunting camps of the fianna were located near peat bogs because peat bogs were natural meat storage facilities, where large amount of meat from fish and animals killed during the summer hunting season could have been stored and preserved until it was needed later in the year? I believe so. 
But fulachta fiadh which were built in waterlogged acidic soils near peat bogs were not just used for food preservation. The animals, both terrestrial animals and fish, whose meat was preserved in bog water also had skins and they needed to be preserved to. As I already wrote in my post “Fulacht fiadh – tannery“, the Bronze Age hunters had several ways of preserving the animal skins and turning them into leather or pelts: vegetable tanning, brain tanning, urine tanning and bran (flour) and salt tanning. All these tanning methods are more or less well known. But there is another tanning method that Fianna could have used, which is almost completely forgotten. 
Peat tanning. 
While I was researching animal skin tanning I came across acid tanning, or pickling. Now acid tanning is not really the best description of this procedure. It should more precisely be called bran (flour), salt and acid tanning. It is basically the same procedure as wet bran (flour) and salt tanning used in Serbia except that additional acid is added to the tanning solution. You can read about the bran (flour) salt tanning in my post “Fulacht fiadh – tannery”. Acid tanning is a very fast way to tan animal skins and uses the same principal used in pickling vegetables. Skin is immersed into strong pickle (salty acidic liquid) which kills all bacteria in the skin and also dissolves all non structural proteins and fats in the skin making the skin thinner and easier to work with. 
Here is a short summary of the acid tanning procedure which you can find online on many websites. I will use it to explain how a fulacht fiadh could have been used for this type of tanning. 
According to the most acid tanning instructions, the chemicals required for acid pickling are:
27 liters water
1 kilo bran flakes
1 kilo of plain or pickling salt (not iodized)
0.45 liters of battery acid (from auto parts store)
1 kilo of baking soda
This is a very good video showing how to do acid tanning using battery acid. Any strong acid can be used for skin tanning but battery acid seems to be most popular.
If your fulacht fiadh trough has volume of 150 liters, you would need 5,5 kilos of bran, 5,5 kilos of salt, 5,5 kilos of wood ash and 150 liters of acidic bog water.
“Make sure the skins were fleshed, membraned and salted immediately after the animals were skinned. If the skin was dried for temporary storage, soak the dried skins in clear, fresh water until flexible. “
The streams near which most of the fulachta fiadh were built come handy here. 

“Boil 12 liters of water and pour over one kilo of bran flakes. Let this sit for an hour, then strain the bran flakes out, saving the brownish water solution.” 
Bran doesn’t really need to be taken out of the solution for it to work. You will just have to later get all the bits out of the fur. So here is how you could achieve this part of the procedure in fulacht fiadh. Let the fulacht fiadh trough fill with fresh bog water, or marshy acidic water into which you have added some wet peat to increase acidity. Leave it to sit exposed to the sun for a day, maybe two. Then boil the water using fire heated stones. Once the water was boiled add bran to it and stir it for a while, and then leave it sit for an hour. 
Next, bring the remaining four gallons of water to a boil. Put the 16 cups of salt in a plastic trash can. Pour the water over the salt and use the stirring stick to mix until the salt dissolves. Add the brown bran liquid. Stir.
Add more hot stones to the trough until it boils again. Then add salt and mix well so that the salt is all dissolved. 
“When this solution is lukewarm, you are ready to add the battery acid. Read the warning label and first aid advice on the battery acid container. While wearing gloves and an old, long-sleeved shirt, very carefully pour the battery acid down the inside of the trash can into the solution — don’t let it splash. Stir the battery acid in thoroughly.”

This part can be skipped. We have started with the acidic bog water, which should by now be even more acidic because of the solar radiation and the work of lactic bacteria which is busily decomposing bran and organic matter from the peat and adding lactic acid to the mix. 
Add the skins to the solution and stir, pressing the skins down carefully under the liquid with the stirring stick until the skins are fully saturated.
Well, get your skins from the stream. They should be nice and plump now. Squeeze the water out of them and then dunk them into the fulacht fiadh trough. 
Leave the skins to soak for 40 minutes, stirring from time to time to make sure all parts of the skins are exposed to the solution.
I have found recommendations that go from 40 minutes (most common) to 20 days but mostly the duration of pickling is less than an hour. The time it takes to thoroughly pickle the skin will vary depending on the thickness of the skin. You can tell it is completely pickled when the skin is a milky white color all the way through, with no pink color. It is very difficult to say how long it would take to pickle skins in fulacht fiadh trough using bog water as acid solution. But we can try to guess. As I already said, the tanning solution used in the so called “acid tanning”, and which we have created in the fulacht fiadh trough, is basically the same solution used in wet bran (flour) and salt tanning in Serbia, with additional acid added to it. Considering that in Serbian wet bran (flour) and salt tanning procedure the skins are left in tanning solution for 3 days, I would say that the time we need to leave skins in the fulacht fiadh trough for anywhere between one hour and 3 days. We should stir the the skins from time to time to make sure all parts of the skins are exposed to the solution. We should also examine the skins from time to time and check if they were white all the way through. 

“Fill your other trash can with clear, lukewarm water. After the soaking is complete. Use the stirring stick to carefully move the skins one by one into the trash can with clear warer. This is the rinsing process, which removes the excess salt from the skins. Stir and slosh the skins for about five minutes, changing the water when it looks dirty.”

Take the skins out of the fulacht fiadh trough. Take them to the stream and wash them thoroughly until the water coming out of them is clear. 

“At this point, some people add a box of baking soda to the rinse water. Adding baking soda will neutralize some of the acid in the skin – this is good because there will be less possibility of residual acid in the fur to affect sensitive people. However, this also may cause the preserving effects of the acid to be neutralized. You need to make the choice to use baking soda based on your own end use of the skin. If skin or fur will spend a lot of time in contact with human skin, use the baking soda. If the pelt will be used as a rug or wall hanging, you are probably ok not to use baking soda.

If you decide to use baking soda, place the hide in the neutralizing solution, and stir for 20 minutes. Remove the hide from the neutralizing solution, rinse, and drain.”

If you want to wear the skins you are treating or use them as bed covers, you should probably neutralize the acid in them. This is how to do it. You can’t use fulacht fiadh trough for this, as it will fill with acidic bog water as soon as you empty it. You will have to use either large pots, like large funerary pots, or you will have to take the skins to another fulacht fiadh which is built in a dry well drained soil and use the trough there, Whatever you decide to do, you will need to use something in place of baking soda, as it was not readily available in Bronze Age Ireland. Baking soda is Alkali. In chemistry, an alkali is a basic, ionic salt of an alkali metal or alkaline earth metal chemical element. An alkali also can be defined as a base that dissolves in water. A solution of a soluble base has a pH greater than 7.0. Now when you mix acid (pH < 1) and alkali (pH > 7) you get salts and neutral pH. So where do we find an alkali that can be used instead of baking soda, and that we can use to neutralize acid in the skins we have just pickled?

The word “alkali” is derived from Arabic “al qalīy” (or alkali), meaning the wood ashes, referring to the original source of alkaline substances. A water-extract of burned plant ashes, called potash and composed mostly of potassium carbonate, is mildly basic. After heating this substance with calcium hydroxide (slaked lime), a far more strongly basic substance known as caustic potash (potassium hydroxide) can be produced. But for de-acidifying our skins, we need ordinary weak base – potash. So grab few handfuls of wood ash from your fireplace and chuck it into the pot or fulacht fiadh trough full of clear water. How much will depend on volume of your vessel. For a 150 liters trough you will need 1 kilo of ash. The major components of wood ashes are potassium carbonate (potash) and sodium carbonate (soda ash), and their average pH is about 9,5 while the pH of baking soda is 9.  Mix the solution. Submerge your skins in and leave them soaking for not more than 20 minutes. If you leave your skins in the potash solution for too long, the hair will start slipping (falling off), which is exactly what potash is used for in bucking, as I already described in my post “Fulacht fiadh – tannery”.

Remove the hide from the rinse and hang over a beam to drain. Rub it with some oil, like neatsfoot oil, salmon oil, beechnut oil, to condition the skin.

Hmmm. I am not sure what kind of oils Bronze Age Irish had access to. Probably salmon oil and beechnut oil. So, get the skins out of the potash soulution, squeeze them and then leave them over a branch to drain. Get some oil and rub it into the skins.

Stretch the hides on a stretcher or hide dryer to finish the process. Place it in a place out of the sun to dry. After a few days the hide should feel dry and flexible. Take it down from the rack and go over the skin side with a wire brush until it has a suede-like appearance. Let the hide finish drying until it is fully dry, which should take a few more days.

This is exactly the same drying procedure used in Serbian wet bran (flour) and salt tanning procedure. Get the skins onto a rack and place them in a shade to dry. Keep an eye on them so that they don’t get chewed on by wolves and such things….Take them off when they are dry and that’s it…
Now here is the problem with using bog water for this type of tanning. 
The recommendation that I found online is that no matter what acid you use, after mixing the pickle up, the pH level should read below a 2.0. Usually it reads 1.1. You should not let the pH go above 2.5 during pickling, and definitely not above 3.0, because then bacteria will continue to grow. Is our day old bran fortified peat water acidic enough? I have no idea. But as I already said, the tanning solution used in the so called “acid tanning”, and which we have created in the fulacht fiadh trough, is basically the same solution used in wet bran (flour) and salt tanning in Serbia, with additional acid added to it. So if bran (wheat) and salt solution is enough to pickle the skins, I would guess that adding highly acidic bog water, which is more acidic than normal vegetable pickle solutions, should make the process even more effective. We know that the pH of the bog water is between 3-4 and that it increases when exposed to sunlight. Is it possible that the final solution has pH below 2,5? Possibly. Whatever the final pH of bog water is, we know that bog water can be used for skin and hair pickling and turning of row skins into pelts and leather. 
The proof are bog bodies.

bog body is a human cadaver that has been naturally mummified in a peat bog. Unlike most ancient human remains, bog bodies have retained their skin and internal organs due to the unusual conditions of the surrounding area. These conditions include highly acidic water, low temperature, and a lack of oxygen, and combine to preserve but severely tan their skin. While the skin is well-preserved, the bones are generally not, due to the acid in the peat having dissolved the calcium phosphate of bone.

The oldest fleshed bog body is that of the so called “Cashel Man“, who dates to 2000 BCE during the Bronze Age.

The best preserved bog bodies in Ireland are:

Clonycavan Man, an iron age bog body dated to 392-201 BC

Oldcroghan Man, an iron age bogman dated to 362-175 BC

The best preserved fleshed bog body is that of the so called “Tollund Man“. Tollund Man is a naturally mummified corpse of a man who lived during the 4th century BC.

Now some people will say: “Well these are preserved because they have been kept inside the bogs in anaerobic acidic conditions for thousands of years…The conversion of skin to leather took a long time….This was not a practical procedure which could be used for tanning animal skins…”

Well I am not surprised that you might say that. I had the same doubts myself. But then I came across this. 

Tanbark is the bark of certain species of trees (such as oak) which has high tannin content. It is traditionally used for tanning hides into leather. In some areas of the United States, such as northern California, tanbark is often called “mulch,” even by manufacturers and distributors. In these areas, the word “mulch” may refer to peat moss or to very fine tanbark.
In “A Dictionary of Science” edited by William Thomas Brande and published 1842 we can read that “attempts have been made to separate astringent matter from peat and to use it in tanning leather”. 
So it seems that people in the 19th century believed that peat water could be used for tanning leather. Why did they think that? Well because peasants living near bogs have been using bog water for tanning leather for millennia. 
One place where we have records of the use of peat tanning is Strathearn in Scotland.  The Strathearn area of Perthshire lies near the centre of mainland Scotland where Lowlands meet Highlands. It includes the towns and villages of Auchterarder, Blackford, Braco, Bridge of Earn, Comrie, Crieff, Lochearnhead, Muthill & St Fillans. On the blog “PerthshireCrieffStrathearn Local History” in the article “The Rise and Demise of the Leather Tanning Industry in Crieff & Strathearn in the 18th and 19th Centuries” we read this:
Tanning in the Strathearn  area had been carried out for many years and was known as  “peat moss tanning” . The hides were immersed in a peat hole and left to allow the tannin from the peat to seep into them thus producing a primitive sort of leather. This method began to die out towards the end of the 18th century. The hides would get as tough as a wooden board. Later the shoe maker would come and heat the leather over a fire while rubbing grease into it till it was flexible and make brogues for the family.
This is very interesting don’t you think. Well a certain Ernest Edward Munro Payne certainly though so. There a US Patent US1040400 A granted on Oct 8, 1912 to Ernest Edward Munro Payne which describes use of peat water in leather tanning. 
Be it known that I, ERNEST EDWARD Monro PAYNE, a subject of the King of England, and residing at Aylesbury, in the county of Buckingham, England, have invented certain new and useful improvements in the production of leather, of which the following is a specification. The characteristic feature of this invention is the use, in the production of leather, of a solution of humus (peat) which consists of humic acid, ulmic acid. According to this invention, in producing leather from skin, the skin is prepared as for tannin and is thereafter treated with a solution of humus in alkali (wood ash) and with an acid.
In “The Natural and Agricultural History of Peat-moss Or Turf-bog” by Andrew Steele we can see that originally people believed that the tanning ability of bog water came from tannins from trees which were disolved in the bog water:
Water flowing out of bogs has a characteristic brown color from dissolved peat tannins. However the active tanning ingredient in peat is not tannic acid which indeed is found in most plants, but ulmic, humic and crenic acids. However these acids have the same effect on the skin as tannic acid. 
On top of this, because  peat consists of bits of the plant called sphagnum moss, commonly known as peat moss, it has some additional characteristics which even more increase its tanning ability.
In the book “The Scientific Study of Mummies” by Arthur C. Aufderheide, we can read this chapter about how sphagnum creates tanning effect in peat moss:
So what does science have to say about the ability of peat water to tan skins into leather? Well some scientists are still pondering:
Three types of humic acids of different sources have been analysed in order to quantify the functional groups that may be liable to react with the proteins of leather. The quantification serves to determine the extent to which each of these acids can be used as tanning or retanning agents. Humic acids have structures similar to those of vegetable tannins.
Translated into English this means that humic acid found in bog water could have the same or very similar effect on skin turning it into leather, just like tannic acid found in plants. 
But some other scientists have confirmed that skin submerged into bog water “becomes bio-resistant” basically turns into leather…
Films of mackerel (Scomber scombrus) skin became brown and completely bio-resistant after repeated immersion in aqueous (3% w/v) sphagnan with intermittent drying. Differential thermal analysis (DSC) of the sphagnan-treated skin gave results consistent with tanning by covalent cross-linking.
We have evidence that until recently people actually used bogs deliberately to preserve food and skin. Even patents were proposed for commercial, industrial use of this technology. 
This sheds a new light on the bog bodies and bog butter… 
What I am trying to say is that people could have deliberately placed food and bodies into bogs to preserve them… To make a miracle preservation pit, you don’t need a fulacht trough. All you need is a pit, a hole in the bog, which will fill with bog water. And if you want to use fulacht which is not located in the bog proper, but in the waterlogged marshy area near the peat bog, just dig some wet peat, dunk it into the trough which is already filled with acidic water and mix….
Is this why some fulachta fiadh were originally built in waterlogged acidic soils near bogs? I believe so…

Fulacht fiadh – tannery

In my last post “Fulacht fiadh – meat and fish curing facility” i said that fulachta fiadh were also called Fulachta Fian and were believed to be the cooking place of the Fianna, small, semi-independent warrior bands in Irish mythology. I also said that Geoffrey Keating, in his 17th-century History of Ireland, says that during the winter the fianna were quartered and fed by the nobility, during which time they would keep order on their behalf, but during the summer, from Beltaine to Samhain, they were obliged to live by hunting for food and for pelts to sell.
As I said in my last post, this was very interesting. If Fianna were “obliged” to live by hunting for food and for pelts to sell, they were basically full time, professional meat and fur hunters. Professional seasonal hunters have two problems that they have to solve if they want to profit from their hunt: How to preserve and store meat and skins. 
In my last post I talked about how the ancient Irish could have solved the problem of preserving and storing large quantities of fish and meat. 
In this post I would like to talk about how they could have solved the other problem: how to preserve and store large amount of animal skins and furs they would have accumulated during their seasonal hunt. 
The process of preserving animal skins aims to make animal skins resistant to bacterial decomposition and weather. This process is quite complicated and consists of many steps which have to be performed correctly and in strict order or the skins will be spoiled. 
I will here list these steps, based on an instruction for deer skin preservation process from the Wilderness Institute web page. And I will explain how fulachta fiadh could have been used in this process. 
Hang the deer upside down to a branch. Cut the belly open and gut and clean the animal. Cut the around the hocks and then along the legs from the hocks to the beely cut. Put the knife away and removing the hide with a fist, not a knife. This is to prevent any knife or score marks on the hide. Score marks now will become holes later. This is a very good video showing how to skin a deer using this technique
Remove any meat and fat from the hide using scraper. You can use a metal scraper (a blunt long blade). Traditionaly a bone scraper made from a deer ulna bone was used
Salting is what sets the hair and keeps the hide from decaying. The moisture content of hides and skins is greatly reduced, and osmotic pressure increased, to the point that bacteria are unable to grow. There are two ways of salting the skins: wet salting and brining. 
But theoretically, all hides are brine cured. Crystalline sodium chloride, or common salt, cannot be absorbed by the hide. Only after the salt crystals have been dissolved in water to make a brine can the curing proceed. In the case of the conventional method (pack curing), the salt crystals draw moisture from the hide which dissolves the salt creating brine. 
In wet salting, the skins are heavily salted using fine salt by rubbing the salt into the inner side of the skin or hide. After salting, hides are rolled up and placed on an incline to allow fluids to drain away from the hide. After approximately 12 hours the skins are unrolled and all of the wet salt is shaken off. A new layer of fresh salt is applied to the skin as explained above. Skin is rolled again and left to rest for additional 12 hours. If after these 12 hours, the skin still appears excessively wet, the salting process is repeat again. If however the skin appears to be drying, with no more fluid draining from it, it can be hung up across a rack to finish drying for another 24 hours.
In the brine curing process, the hides are in contact with saturated brine at all times. This serves to reduce the time required to cure hides to about 16 hours. The hides have to be constantly turned and agitated to ensure that every part of the skin is properly soaked with brine.  
Both of these salting methods would involve use of fulacht fiadh. 
If wet salting was used, salt was probably grabbed from leather sacks or pots where it was kept and then applied to the skins by rubbing. The excess salt which was brushed off the skins at the end of each salting stage, could then have been collected and eventually purified and reclaimed through boiling in the trough using fire heated stones. 
If brining was used, brine was made in the trough. Different size skins require different size troughs to insure the skin was completely submerged and not tightly folded. This could account for great variety in fulacht fiadh trough size. At the end of the brining process the remaining salt could have been reclaimed from brine  through boiling in the trough using fire heated stones. 
This of course could only have been possible providing trough was made watertight. If not the brinning solution would either be diluted or chemically changed by influx of water from the soil, if the fulacht fiadh was located on marshy, waterlogged terrain, or the brine would disappear into the ground if the fulacht fiadh was located on dry well drained soil. 
At the end of the salting procedure, if the above steps were followed and completed carefully, the skin should be in a stable state. A stable state is when the skin can be safely left as it is for a period of time, even months, without fear of hair slippage or spoilage. This means that the process of preserving the skins can be interrupted at this point and continued at some later more suitable moment, like during the winter, after the end of the hunting season. 
It is quite possible that this was the end of the animal skin treatment process which was performed in summer camps. The skins would be salted and stored safely in a tent or in a wood lined pit dug in the well drained ground. They would then be carried to the village where the rest of the skin preservation process which turns skins into leather and pelts was carried away. 
There is one thing I have to add about salting. Salting is not a mandatory part of the animal skin preservation process. Salting is used in cases where there is a long enough period between the skinning and the rest of the skin processing. Bacteria in the skin will start decomposition pretty much straight away and even if only couple of hours have passes between skinning and the next processing stage you will be better off using salting to make sure the decomposition was stopped. But if you are going to flesh and wash the skin straight away after skinning, then salting is not necessary. You can basically just wash, stretch and dry the fleshed animal skins completely. You can then store these dry skins in a dry airy place for months until you decide to continue the skin preservation process. This is very important. As I already explained in my post “Fulacht fiadh – salt pan”, salt was a rare and valuable commodity in ancient Ireland and I doubt the Fianna hunters would use salt for treating animal skins unless it was absolutely necessary. 
Now next stage in animal skin preservation depends on whether you want to produce leather (hareless skin) or pelts (hairy, furry skin).  If you want to produce leather, then the next thing you need to do is bucking followed by rinsing, graining and membraning and then rinsing again.
“Bucking” is the soaking process in the solution of lime or lye (wood ashes) the hide is soaked in to remove the mucus in the collagen layer of the hide, as well as to loosen the hairs. It’s the mucus that prevents the tanning medium from adhering to the fibers in the hide. You have to make sure that the bucking solution is not “too strong” which is possible with hardwood ashes, especially with ashes from woods such as oak and maple (the hard, dense woods). A good way to test how strong an ash solution is: float an egg, it should have a thumb nail sized portion floating above the solution (it has to actually float, not sit on top of the settled ashes); barely floating means a weak solution, tipping over means a strong solution.  
So mix wood ash into the water, float an egg to determine proper concentration of hard wood ash, then soak hide until hair slips. The skin should soak until the hair pulls free easily. If the water is about 20 degrees Celsius it should slip in about 3 days. 
This is another part of the animal skin preservation process which could have been done in fulacht fiadh. A trough would be filled with water. For this to be manageable fulacht fiadh would need to be located next to a water source, as they all are. Ash from camp fires would then be added to the water and mixed in to form bucking solution. When bucking was finished, remaining bucking solution could be scooped out of the trough using cups or pots and spilled on top of the burned mound. Or the water could have been evaporated from the trough using fire heated stones, and the ash then scooped out. 
Again, this could only have been possible providing trough was made watertight. If not the bucking solution would either be diluted or chemically changed by influx of water from the soil, if the fulacht fiadh was located on marshy, waterlogged terrain, or the bucking solution would disappear into the ground if the fulacht fiadh was located on dry well drained soil. 
Graining means removing the hair and grain, the part of the skin that holds the hair. Any grain will make the hide stiffer and will prevent the smoke from entering the hide when smoking the hide latter on. This means you are scraping the outer side of the skin. Traditionaly a bone scraper made from a deer ulna bone was used. It works great but must be sharpened through out the process. 
Drying Skins
After the hides have been grained set them in the sun to dry. This should not take any more then an hour on a dry day. This drying will make the membraning much easier and productive.
Dunk skins into a river or a stream to get them thoroughly wet. Another reason why fulactha fiadh would need to be built next to rivers or streams. This should not take more then about 15 min.
Removing the membrane
By the way bucking also works on the inner side of the skin softening any remains of meat, membrane and other tissue left after skinning. So during graining you can revisit the inner side as well and remove what ever was left clinging to it.
Using the fleshing tool remove the membrane which is what holds the blood vessels. Like the grain, if any membrane is left the hide will be hard and will prevent the smoke from penetrating the hide. You are now working the inner side of the skin. This part of the processing is done as part of fleshing if you want to produce pelts and not leather. 
After the membrane has been removed, put the skins in a gunny sack tied off in a river or a stream and leave them overnight. Again it is handy if your camp is next to the river or a stream…
Next morning the skins should be thin. Wrap the hide so it forms a donut with the outside of the skin out. Wring in one direction then the other, then rotate the hide and do it again. Do not let the dry out you want the skins thirsty but not dry.
Opening (stretching) the skin
Opening the skin will make the skin be thirsty and will do a better job of taking up the tanning agent. 
At the end of this part of the process we have so called “stable” skins, skins which can be stored indefinitely and even used inside where they are not exposed to the elements. They can be smoked to be made more durable and resistant to bacteria and insects. But if you want your skins to be resistant to water and not go cardboard hard ever time they get wet, they need to be tanned, oiled and softened and smoked.
Here you can choose which tanning solution to use to tan your skins. Four traditional and tanning processes that have been used for thousands of years in Europe are vegetable (wood) tanning, brain (oil) tanning, urine tanning and bran (flour) and salt tanning. 
Bark tanning
Tannins are chemicals, more precise acids, which occur naturally in most plants in various amounts. They transform proteins into insoluble products that are resistant to decomposition and this is why tannins are used as tanning agents for leather.
Tannins occur in nearly every plant. It is found in almost any part of the plant, from root to leaves, bark to unripe fruit to nuts and acorns, but it is most concentrated in the bark layer where it forms a barrier against microorganisms such as fungi and bacteria. Typical materials used for bark tanning include any of the oaks, fir, certain willows, chestnut…
If you want to use bark for tanning extract it is best to collect it in the spring. This is when the bark has the highest concentration of tannins and is the easiest to peel, but you can use bark from any time of year. Supposedly, an older tree has more tannin than a younger one, and the lower parts of the tree contain a higher concentration than the top parts. 
Now getting the bark off trees, even if you don’t cut the tree down, will kill the tree. It is good then to know that you can extract tannins not just from bark but also from acorns, oak galls and even leaves (as you can see in this video). 
How do you extract tannins out of the bark? You leach them out. You dry the bark, crush it, pound it into a pulp and then cook it. Tannin is water soluble. The warmer the water you soak the bark in the faster the tannin is extracted. But hot water darkens tannin resulting in a darker colored leather. Now remember my post “Fulacht fiadh – acorn leaching pit“? What i described in that post was a way fulacht fiadh could be used to leach tannins out of acorns. Basically you would fill the fulacht fiadh trough with water, heat the water using the fire heated stones, then dump a lot of shelled and crushed acorns into the trough, and keep simmering them, occasionally changing water until all the tannins were leached out and the water is finally clear. Here you can see what tanned water produced by leaching acorns looks like.

The same leaching procedure can be used for extracting tannins from barks. The tanned water which results from this procedure can be scooped out of the fulacht fiadh trough and collected in large clay vessels. It can then be boiled and concentrated. The concentrated tannin rich “tea” can then be poured back into the trough and used as tanning solution for animal skins.

Soaking of the skins in tanning solution should be done first in a relatively weak solution and then in progressively stronger solutions. It is very important to use a very weak solution for your first bath. If the hide is put into a strong tannin bath, the outside gets tanned and shrinks. This inhibits the tannins from penetrating to the center of the hide, leaving the inner parts raw. This is called “dead tanning” or “case hardening”. The ideal bath to start with is one that has already been used for another hide. That way all the large tannin particles have already been used up. This is known as a “spent liquor”. There is another advantage to spent liquors. In an old bark liquor, the bark sugars have fermented, forming lactic and acetic acid, which help remove any traces of lime as well as help preserve the hide. 

The skins should then be left in the strong solution for as long as it takes for the solution to penetrate all the way to the center of the skin. But how long that is depends on the thickness of the skin and can go from few weeks to few months. Here you can see skins submerged in the tanning pit and the pile of oak bark next to the pit, used to make tanning liquid. Fulacht fiadh trough uses for skin tanning would look very similar to this. 

During the soaking period, fulacht fiadh trough containing skins submerged in tanning solution can be covered with planks or split branches and then covered with hide and soil or peat. From time to time it can be checked on and more tanning concentrate or raw bark can be added to strengthen the tanning solution. 

Eventually the skin is taken out of the tanning solution. It then needs to be rinsed in running water (river, stream next to which fulachta fiadh were usually built) and squeezed and rinsed and squeezed…Until it is rinsed I suppose. 🙂
The skin then needs to be oiled. Oiling the bark tanned skin makes it dry softer, darkens it and prevents it from cracking. Vegetable oils (beach nut oil), tallow, brains, bear and boar fat and fish oil have all been used to finish bark tanned leather. The hide that is being oiled should be damp. It should then be stretched in all directions. Oil should then be spread evenly on the skin and the if you want soft leather the skin should be worked soft as it dries. When the hide is dry, it can be lightly dampened and then oiled and worked again. This process of oiling, working and drying can be repeated until you get the softness you desire. 
This is a good video showing primitive bark tanning of animal skins. 
Brain tanning
This is truly ancient tanning method. It is quick and well suited for single skin processing in the wild. And as opposed to bark tanning it is environmentally friendly. 
There are two distinct methods of brain tanning, one in which you apply tanning solution onto the skin and the other in which you soak the skin in the tanning solution. 
Making the brain solution
Every animal has enough brains to brain tan its own hide. Except for buffalo for which you need brain and bone marrow. To prepare brain tanning solution use warm water but not too hot.  A good rule of thumb is that if its too hot for you, its too hot for the animal. Too hot will ruin the hide.  You have to mix the brains from the animal into warm water and mash them up into a paste. 
Applying the brains
The biggest trick to good brain penetration is proper hide moisture content. You want the hide damp in that you can not squeeze and moisture from it, but feels like a sponge. Too dry and the pores will be too tight to let the brains through, too damp and the pores and fibers will be too full to let anything else in. 
Rub the brain mixture into the stretched hide until it is thoroughly saturated and soaked in. If you are treating hair on hide, make sure you only apply brain solution on the inner side of the hide, as it will make the hair slip if applied on the outer hairy side. Wait until the skin almost dries, then apply the brain solution again. Wait until skin dries again. Remove it from the frame and soak it in water again and then wring it out. Stretch it on the frame again.  
This series of videos shows how to brain tan a bear on a frame. This part shows applying brain tanning solution on the skin stretched on a frame.
But the skin doesn’t need to be stretched on the frame for brains to be applied to it. This is a very good series of videos showing how to apply brain solution on a skin stretch flat on the ground.
After the skin has completely dried out, it needs to be softened. This is done by simultaniously stretching and rubbing the skin. If the skin is stretched on the frame, the softening is done by pushing and scraping the hide with a blunt stick. You have to make sure that every bit of skin is pushed and shoved and scraped… 
Otherwise you can use a pole, a tree stump, a rope or anything else that you can stretch the skin over and pull it from side to side. Here you can see softening of the hide on a stump. 
Regardless how you decide to soften the hide, you have to keep the hide in motion stretching, pulling, pushing for a very very long time. This is a hard process which is continued until the hide is soft. If it gets hard in any places it is because those places dried without being in motion. Rehydrate that part the skin and continue to soften it until it is dry and loose.
In order to make a brain tanned hide resistant to water, it has to be smoked. Otherwise the hide fibers would glue themselves back together again and the hide would become hard. The resins in the smoke penetrate the hide and prevent them from gluing them back together again if they get wet.
Smoking of hides is identical to cold smoking of meat. You need to place the hide on some kind of frame over a smoldering file. If you are smoking one hide or few hides you can just make a temporary tripod from sticks and spread the hide over it, inner side in. 
Then you place the tripod over a fire. This needs to be a cool smoking fire made with punkwood. Punkwood is the wood from any tree that is in a stage of decay where it feels almost styrofoam-like in consistency… very light and slightly squishy.

You have to make sure that the smoke rising from the fire is cool and damp. If the smoke starts to feel dry add more punkwood. It the fire stops smoldering and starts to flame the hides will be ruined. Hides will need to be smoked like this for several hours. Or you can hang the hides under the roof of your wigwam or round house and let them smoke over constantly smoking heart fire. As I already wrote in my post about Curing = Smoking, this is probably how the curing ability of smoke was originally discovered. After the smoking is done, the brain tanned hide will be water resistent. 

Urine tanning

In ancient history, tanning was considered a noxious or “odoriferous trade” and relegated to the outskirts of the town, among the poor. This is because Old Mediterranean and Messopotamian cultures for some reason thought that the best tanning agent was urine. And poo. 
Is this why there are no fulachta fiadh inside villages?
Urine tanning is one of the oldest tanning methods. And one of the stinkiest. Urine tanning consists of dunking skins in a half – half mixture of water and urine and leaving them to soak for a period between 1 day (Source: “Leather – Preparation and Tanning by Traditional Methods” by Lotta Rahme) for fish skins to 30 days for hides with fur. 
Why use urine? Urine contains ammonia, and ammonia is an amazing basic solvent that can break down fats and oils, clean surfaces and stop decay from forming. When our bodies and the bodies of all mammals break down amino acids as a part of normal metabolism, we produce ammonia. Since ammonia is toxic to us while in our bodies, our livers covert that ammonia into urea and salts, which we excrete in our urine. But that separation is only temporary. If you leave the urine to lie around for any amount of time, the urea and salts will start binding back together to form ammonia again. This is why it is the stale pee that is used in tanning.
In order to tan skin with urine, you need to have enough urine to completely submerge the skin in it and have it float without being tightly pressed. Basically what you want is that every bit of the skin is in contact with urine water mixture. For a salmon skin or a small animal like squirrel this means 4 – 8 liters of urine per skin. For larger animal skins you will need a lot more. Normal daily output of urine for an adult is one to two liters per person. So a group of 10 hunters would be able to collect say average 15 liters of urine a day. If an average fulacht fiadh trough contains about 200 liters, they would need 80 liters of urine to make 160 liters of urine water mixture and fill the trough. To collect this volume of pee would take about a week. And where you might ask yourself would the fianna collect their pee in? Well how about the fullacht fiadh trough…Every morning fianna members would emerge from their camp shelter, bloated from all the fulacht fiadh brewed beer they drank previous night. They would gather around the fulacht fiadh trough and then….
As I said, I would take a 10 man hunting band a week to 10 days to fill the trough. During that time they would skin killed animals, flesh and membrane the skins, rub them with urine or mixture of ash and urine to help get rid of hair (if they were making leather rather than pelts) and would then grain the skins wash them and dry them in the sun. These stable skins would then be stored in one of the shelters until the fulacht fiadh trough was full of pee. 
Collection of urine for tanning is well documented, The so called “piss-pots” were located located on street corners, where human urine could be collected for use in tanneries or by washerwomen. So theoretically our fianna boys could have collected new urine in large beakers 🙂 while the skins were pickling in fulacht fiadh trough full of old urine. This way there would be no pause in the trough use…
Once the trough is filled the skins can be then be submerged in the tanning solution and left there until they have been properly tanned. After the skins are submerged and stirred the trough should be covered with hide pressed with stones to prevent excessive evaporation of ammonia. 
You’ll check the skin every day and give it a stir.  It shouldn’t smell too awful, and if it does, you need fresh solution because bacteria has set in. I couldn’t find any instruction how do you distinguish between awful and too awful…I guess years of smelling old pee baths filled with decomposing animal skins will teach you….
Once curing is finished, the skins need to be taken out of the trough. The trough would then need to be emptied of used pee water solution, as it should only be used once. And the new cycle of pee collection would start. As for hides, they would need to be thoroughly washed in water. Few times….It helps if its rubbed in with soap and then rinsed several times. Ancient Irish could have used soap made from camp fire ashes and animal fat. It is also possible to make a warm solution of soap mixture in water, let it cool and then soak the skins in it. You can then make a scented solution of strong smelling barks and flowers in water (tea) and then soak the skins in this water…North American Indians used this type of skin washing procedure after pee tanning. However, even after all this washing, the skin will stink like old pee when wet but as it dries that smell will go away. However some people say that it is the stink that goes away but the smell never really goes away…
Anyway, smelling or not, washed skins would then need to be dried properly. After that it would need to be oiled and stretched and softened. The urine tanning leaves skin very pale. So If you want to change the color of the skin, you can then tan it using vegetable tannins. And then smoked. And that is it. 
Again, the use of fulacht fiadh trough as a tanning vat, could only have been possible providing trough was made watertight. If not the tanning solution would either be diluted or chemically changed by influx of water from the soil, if the fulacht fiadh was located on marshy, waterlogged terrain, or the tanning solution would disappear into the ground if the fulacht fiadh was located on dry well drained soil. 
Bran (flour) and salt tanning
I came across another very interesting way of tanning pelts, which is not very well known: wheat (oat) tanning. This type of tanning was in Scandinavia used to tan sheep skin rugs, and in Serbia, Romania and probably other places for tanning sheep skin for coats. This is how you do it:
Two handfuls of flour and one handful of salt was rubbed into the fleshed and membraned inner side of the skin. Then the skin was folded, a weight is put on and it was then left in a dry place to set for three days. After 3 days, the flour and salt were scraped off the skin and skin was stretched and broken until soft. Finished!
A skin treated like this will be white and relatively brittle. The Scandinavian rugs where used mainly as bed covers, if kept dry, they could last for a lifetime and more.
The process of tanning sheepskin was practiced by most of the peasants at home, with traditional techniques.
Boiled salty spring water (brine) was let to cool down. Oat flour and wheat bran were added, while stirring. The sheepskins were then treated with this mixture and folded, for 3 days. After 3 days, they were dried, then cleaned and stretched and softened.
In Serbia salt and flour tanning is done in two ways: dry and wet. 
Dry tanning
Stretch well washed, fleshed and membraned sheepskin or fur. Rub mixture of flour (bran) and salt into the inner (flesh) side. Leave the skin to dry in a draft our of the direct sun. Once the skin is completely dry tanning is done. The sheepskin or fur is then scraped, brushed and worked to soften. 
Wet tanning
Bran and non ionized salt are poured into luck-warm water (40C) and is left to ferment for 3-4 days. You need 50 – 60 grams of bran and 70 grams of salt per liter of water. Once the tanning solution was ready, skins were submerged in it and left soaking for 1 to 2 weeks. After tanning is done, skins were taken out of the tanning solution, washed, dried, scraped, cleaned, brushed and then stretched, worked until soft. Metal containers and utensils react with salt and rust and should never be used in this type of tanning. So wooden tubs and wooden spatulas or sticks were traditionally used. 
This second procedure could have easily been used for tanning furs in fulachta fiadh. 
Fulacht fiadh troughs which were lined mostly with wooden planks and sometimes with stone plates are ideal containers for this type of tanning. For a 150 liter container (1 meter X 0.5 meter X 0.2 meter), which is an average size fulacht fiadh trough, you would need about 8 kilos of bran and about 11 kilos of salt. To prepare the tanning solution you could pour water into the trough and then heat it using fire heated stones. Once the water is cool enough to put your hand into it, bran and salt could be poured in and stirred. This bran soup would then be left in the covered trough for 3 – 4 days to ferment. The furs were then submerged in the through and pressed with logs so that they don’t float on the surface. The though would be covered again and furs would be left in the tanning solution for one to two weeks. They would be stirred and mixed from time to time to ensure that every part of the skin was in contact with tanning solution. When the tanning was finished, furs would be taken out, dried, scraped, cleaned, brushed and then stretched, worked until soft. The salt still remaining in the tanning solution could be reclaimed by dropping fire heated stones into the trough and boiling the water out. 
After tanning skins were unintentionally smoked. This type of primitive tanning was done by peasants and they lived in very smoky houses with no chimneys. Like this one from Croatia. 
Any skin worn or in any other way used in such houses would soon be completely impregnated with smoke resin and made resistant to elements…
This is a brilliant video showing traditional sheepskin tanning performed by three grandmothers in a village in Croatia. They actually only use salt as a preservative agent, but the procedure is the same as in salt + flour tanning. 
Now we know that Bronze age Irish did grow grains, so they could have used either one of these methods for tanning furs using mixture of salt and bran (flour). By the way this is a very environmentally friendly way of tanning. 
So, there you have it. Geoffrey Keating, in his 17th-century History of Ireland, says that during the winter the fianna were quartered and fed by the nobility, during which time they would keep order on their behalf, but during the summer, from Beltaine to Samhain, they were obliged to live by hunting for food and for pelts to sell. If the Fianna really lived from hunting for pelts to sell, they had to be able to turn animal skins into durable, useful and good looking leather and pelts. To do that they had to preserve (tan) the skins.  And as we have seen Fulachta fiadh could have been used as efficient tanneries (providing troughs were made watertight).  So was this one of the usages of fulachta fiadh? 

Fulacht fiadh – meat and fish curing facility

A fulacht fiadh or fulacht fian  is a type of archaeological site found in Ireland. In England, Scotland, Wales and the Isle of Man they are known as burnt mounds. They commonly survive as a low horseshoe-shaped mound of charcoal-enriched soil and heat shattered stone with a slight depression at its center showing the position of a stone or wood lined pit. In legend, Fulachta Fiadh, which were also called Fulachta Fian,  were the cooking place of the Fianna. 
Fianna (singular fiann) were small, semi-independent warrior bands in Irish mythology. They are featured in the stories of the Fenian Cycle, where they are led by Fionn mac Cumhaill. The historical institution of the fiann is known from references in early medieval Irish law tracts. A fiann was made up of landless young men and women, often young aristocrats who had not yet come into their inheritance of land.
Geoffrey Keating, in his 17th-century History of Ireland, says that during the winter the fianna were quartered and fed by the nobility, during which time they would keep order on their behalf, but during the summer, from Beltaine to Samhain, they were obliged to live by hunting for food and for pelts to sell.
Now this is very interesting. If Fianna were “obliged” to live by hunting for food and for pelts to sell, they were basically full time, professional meat and fur hunters. 
Fulachtaí fiadh are usually found close to water sources, such as springs, rivers and streams, or waterlogged ground. One of the reasons for this could have been because in thick forests rivers and streams are the easiest ways in and out. So a hunting party would naturally follow the river and set camps on its banks, venturing into the forest to hunt and bringing their kill back to the camp to be processed, cooked and eaten or preserved and stored. These seasonal camps were reused year after year and this is what caused accumulation of burned stones. I spoke about this in more detail in my post “Fulacht fiadh – sweat lodge” and in my post “Banya“.

But there is another reason why Ancient Irish hunters would set camps along rivers. Fish. And one fish in particular: salmon. We know that the Bronze Age Irish had been catching and eating salmon on large scales using massive fish traps and weirs. Indeed the oldest fish traps found in Europe were found in Ireland and were used for catching salmon 8000 years ago. 

Now salmon is a delicious fish so no wonder people have been catching it for food for so long. But as any other fish it is highly perishable. Fish can only last 12-15 hours in fresh condition after catching. So if the ancient Irish really did built fish traps to catch fish in large numbers, they must have had a way of preserving this fish for later use. 
It is exactly the same with meat. A dead animal starts rotting straight away. Especially during the warm period of the year, the meat left outside will get spoiled within hours, unless it is preserved. 
In cold and dry areas of Scandinavia, during spring months, it is possible to air dry fish in 3 to 4 days. 
Such dried fish would keep for a long time. Here is an excellent video showing how this is done. But even there, later in the year, during summer and autumn, when the weather gets warmer and more humid, fish needs to be cold smoke dried in order to preserve it. 
So if the ancient Irish used some method for preserving meat and fish it was probably smoking or smoke drying. Smoking can be done with or without salting. However if you salt the meat or fish before you smoke it, it will last much longer. 
I believe that the Bronze Age Irish were perfectly capable of doing both salting and drying meat and fish using fulachta fiadh. And this is how:

Fish first needs to be scaled, gutted and filleted. This can be done in the stream or river or lake.  

After the meat and fish was cleaned, and before it is salted, it needs to be cut into thin strips to enable deep salt penetration and proper aeration and smoke exposure. 

The meat and fish then need to be salted. Salting is an essential feature in smoking both meat and fish. The basic role of salt in curing is to dehydrate the meat and fish just enough so that bacteria cannot thrive. It also works as an antibacterial agent which kills bacteria on contact cleaning the surface of the the meat. Using the plant salts with high level of nitrates is even better, as the nitrates kill botulism bacteria, which normal salts can’t. I talked about these special salts, and the possibility that the ancient Irish could have used them for food preservation in my post “Not all salts were made equal“. Unsalted fish particularly will usually sour or spoil if kept at smoking temperatures for any length of time. 

There are two ways to salt-cure meat and fish.
Dry curing: Salt is rubbed over the meat.
Wet curing: Also known as brining, this involves soaking the meat in a brine, a strong solution of salt in water. 
Dry salting
Meat or fish pieces are rubbed with salt and placed into a dry fulacth fiadh trough. Once all the pieces are placed into the trough, they are covered with salt, then with stone plates or wooden planks and then stones are placed on top to press the content. You need to leave the meat in the salt for 2 weeks. Every few days the meat is repacked, the bottom pieces are put to the top…
Wet salting
To salt a lot of meat of fish, you need a lot of brine and to make a lot of brine you need a large tub. 
On the website of “the New Zealand digital library, hosted by the University of Waikato”, we can find instructions how to salt and smoke fish using primitive techniques. In this instruction we can see a drawing showing a salting tank with dimensions: 
It is strikingly similar to the construction and dimensions of large fulach fiadh troughs.
So where would you make brine in a fulacht fiadh? In a trough of course. The bigger the better. You need to keep the fish or meat covered with brine throughout the brining period. A log can be floated on the brine to keep the fish or meat submersed, but what ever you are salting should not be packed so tightly that the brine cannot circulate around each piece.

The strength of the brine is a matter of preference. Brining duration depends on the type of smoking you want to do. One method of determining the ratio of water to salt is to put all the fish or meat you want to salt into the trough and then cover it with water. Then just keep adding salt to the water until no more salt will dissolve in it. You can test the concentration of the brine by dropping an egg into the water and adding salt until the object floats. 

The salting period is 3 weeks. 

The thing is for either type of salting, the trough would have to be covered with a wigwam, to protect it from rain. 

After the salting, birning is finished, the remaining salt in the brine can be reclaimed by boiling the brine in the trough using super heated stones. This is the exact same procedure used for extracting salt from brine that I described in my post about a possible use of fulachta fiadh as salt extraction facilities

Now that the fish or meat is salted, it needs to be quickly rinsed in fresh water and it can then be hang and smoked. 

The reason why smoking preservers food is predominantly because a number of wood (or peat) smoke compounds act as preservatives. Phenol and other phenolic compounds in wood smoke are both antioxidants, which slow rancidification of animal fats, and antimicrobials, which slow bacterial growth. Other antimicrobials in wood smoke include formaldehyde, acetic acid, and other organic acids, which give wood smoke a low pH—about 2.5. 

In order to be smoked the fish or meat needs to be hanged off some kind of frame or placed on some kind of rack which is then placed over a smoldering fire. 

There are two general methods of smoking: hot-smoking and cold-smoking. 
Hot-smoking (also called barbecuing or kippering) requires a short brining time and smoking temperatures of  52 to 80 °C and smoking duration between 15 minutes and 8 hours. Hot-smoked fish and meat are moist, lightly salted, and fully cooked, but they will keep at the 4.5 °C for only a few days at best. If hot smoking was used, the meat or fish had to be straight away taken to the nearest settlement for sale. 

A simple wooden rack like the one below is sufficient for short hot smoking. 

Cold-smoking requires a longer brining time, lower temperature of between 26-32°C and extended smoking time of one to five days or more of steady smoking). Cold-smoked fish and meat contain more salt and less moisture than hot-smoked fish. Once the fish has been sufficiently cured by smoke, it will keep at 4.5 degrees Celsius for several months. 
There is also a method of smoking that preserves fish and meat in such a way that it will keep for longer than several months in room temperature. 
Basically you need to sufficiently dehydrate it through prolonged process of smoke drying. First you need to thoroughly salt the fish or meat and then you need to press it to squeeze out excess moisture. Then you need to smoke it for four days to a week on continuously smoldering fire. The resulting product is only about one third its original weight, is quite firm and has a glossy surface. This dehydrated fish or meat will keep for an undetermined period, (not indefinite). This is the kind of smoke drying procedure still used by peasants in Serbia. Meat preserved like this can be kept hanging in airy dry place at room temperature for as long as you want. Fish preserved like this needs to be stored tightly wrapped, in a dry place, at low temperature. 
For long cold smoking, and particularly very long smoke drying, there is a risk that it might rain, and rain will completely spoil the fish or meat being smoked. This is why cold smoking needs to be done in a covered space, similar to a sweat lodge. Remember the design for sweat lodges I proposed was used by the ancient Irish in fulachta fiadh? Exactly the same type of hut can be used as a very efficient cold smoker. 
It is amazing how every part of the fulacht fiadh can be used for so many different things…

This type of preserving fish was recorded by the Lewis and Clark Expedition, also known as the Corps of Discovery Expedition. This was the first American expedition to cross what is now the western portion of the United States. It began near St. Louis, made its way westward, and passed through the continental divide to reach the Pacific coast. 

On the website “A history of the Grand Coulee Dam 1801 – 2001” we can read that Lewis and Clark reported that they had encountered Native Americans that dressed similarly to the Nez Perce near the Celilo Falls, who were all drying and pounding fish. Here Clark wrote that he also saw “Several Indians in canoes killing fish with gigs“. Clark details the drying process when he wrote:

“On those islands of rocks as well as at and about their Lodges I observe great numbers of stacks of pounded salmon neatly preserved in the following manner, i. e. after being sufficiently dried it is pounded between two stones fine, and put in a spaces of basket neatly made of grass and rushes better than two feet long and one foot diameter, which basket is lined with the skin of salmon stretched and dried for the purpose, in this it is pressed down as hard as possible, when full they secure the loops of the basket that part very securely, and then on a dry situation they set those baskets the corded part up, their common custom is to set 7 as close as they can stand and 5 on the top of them, and secure them with mats which is raped around them and made fast with cords and covered also with mats, those 12 baskets of from 90 to 100 lbs. each form a stack. thus preserved those fish may be kept sound and sweet several years, as those people inform me, great quantities as they inform us are sold to the whites people who visit the mouth of this river as well as to the natives below
I believe that if the ancient Irish used smoking to preserve fish and meet, they must have used some method of smoke drying very similar to the one described above. And they could have used fulachta fiadh for it. 
So, there you have it. Geoffrey Keating, in his 17th-century History of Ireland, says that during the winter the fianna were quartered and fed by the nobility, during which time they would keep order on their behalf, but during the summer, from Beltaine to Samhain, they were obliged to live by hunting for food and for pelts to sell. If the Fianna really lived from hunting for pelts to sell, they had to be able to preserve a huge surplus of meat they ended up with during the hunting season for the winter or at least for the duration of transport from the hunting camp to the customers in villages. To do that they had to cure the meat through smoking or salting and smoking.  And as we have seen Fulachta fiadh could have been used as efficient fish and meat curing facilities. 

Can you see me?

Gesta Danorum (“Deeds of the Danes”) is a patriotic work of Danish history, by the 12th century author Saxo Grammaticus (“Saxo the Literate”, literally “the Grammarian”).

It consists of sixteen books written in Latin and describes Danish history and to some degree Scandinavian history in general, from prehistory to the late 12th century. In addition, Gesta Danorum offers singular reflections on European affairs in the High Middle Ages from a unique Scandinavian perspective, supplementing what has been handed down by historians from Western and Southern Europe.

The sixteen books, in prose with an occasional excursion into poetry, can be categorized into two parts: Books 1-9, which deal with Norse mythology, and Books 10-16, which deal with medieval history. Book 9 ends with Gorm the Old, the first factual documented King of Denmark. The last three books (14-16), describe Danish conquests on the south shore of the Baltic Sea and wars against Slavic peoples (the Northern Crusades), are very valuable for the history of West Slavic tribes (Polabian Slavs, Pomeranians) and Slavic paganism. Book 14 contains a unique description of the temple at Rügen Island and Slavic pagan rituals that took place there.

The original name of the island Rügen or Danish Rugia at the Baltic Sea was Rujan (meaning red in Old Slavic); thus the name would in translation imply ‘The Red Island’. The autochthonous inhabitants of the island were the Slavic tribe, the Rujani, whose name was cognate with the island’s; thus translating as “people from Rujan” or “red people” or “redheads”??? After the destruction and/or assimilation of the Rujani by the Danes, in 1168, the original Slavic name of Rujan was corrupted as Rügen in German and Rugia in Danish.

According to Gesta Danorum by Saxo Grammaticus, and also Chronica Slavorum by Helmold, the main temple on the Island was located in Arcona, late renamed to Jaromarsburg. The temple was dedicated to the god Svantovit (Svetovid), the main Sun god of the Slavic pantheon, and was used from the 9th to the 12th century. It contained a giant wooden statue of Svantovit (Svetovid) depicting him with four heads (or one head with four faces) and a horn of plenty. 

The temple was also the seat of an oracle in which the chief priest predicted the future of his tribe by observing the behavior of a white horse identified with Svantevit (Svetovid) and casting dice (horse oracles have a long history in this region, being already attested in the writings of Tacitus). The temple also contained the treasury of the tribe and was defended by a group of 300 mounted warriors which formed the core of the tribal armed forces.

The main ritual was celebrated once a year, at the end of the harvest at the beginning of November (Samhain?). All the inhabitants of Arcona gathered in front of the temple on this occasion. On the eve of the celebration the priest, who contrary to the common people had long hear and beard, meticulously cleaned the chapel, to which only he himself had access. The ritual which took place the next day was described by Saxo like this:

The following day, when the people camped out by the temple doors, the priest took the horn from the statue’s hand and carefully examined it to see whether the drink in it was evaporating, which was taken to be a warning that the harvest would be poor the next year, in which case he [the priest] obligated the people to save something of their current harvest for next year.  If the drink did not disappear, that foretold a bountiful year.  Thus, depending on what the horn predicted, he ordered the people either to save their harvests or to use them till they be sated.  Next he poured the wine as an offering at the feet of the statue, filled the horn anew and pretended as if he had drunk to honor him [the God], while at the same time he asked with lofty words for success/good luck for himself and the people of the country, for riches and for victory, and after that he brought the horn to his lips and drank all of it in one gulp, and thereafter he filled the horn again and placed it in the statue’s right hand.

There was also there as an offering an oval-shaped honey cake which stood almost as tall as a man. The priest would place it between himself and the people and asked thereafter whether they could see him [from behind the cake].  When they answered him, he then wished them that next year they should not see him, whereby the meaning of this was such that he did not mean death to himself or the people but rather that the next year should be bountiful [i.e., and the cake bigger].

Next he blessed his people in the name of their God, told them that they should honor Him with frequent offerings, which he expected as a the right payment for [their] victories on the land and sea.  And when this was done, they spent the rest of the day on a great feast, where they ate the offerings [for the God], so that that which was consecrated for the God they themselves ate.  At this feast, it was believed pleasing to the God to get drunk and as a sin to remain sober.

You can find the description of this ritual in “The Handbook of Religions in Ancient Europe” By Lisbeth Bredholt Christensen, Olav Hammer, David Warburton.

The “oval bread” the Slavic priests at Arcona were hiding behind is still made in Serbia as a traditional Christmas cake. The bread is called “česnica” and is an oval bread which is decorated at most with the cross, making it look like the “Celtic cross”. 

This is actually the solar agricultural cross which symbolizes  solar year divided into four parts by two solstices and two equinoxes. Sometimes the cross will have small semi circles on the edges of the cross hands. These are called “hands of god”.  They represent the three months of every season. You can read more about the solar cross in my post “Two crosses“. Česnica can also contain additional decorations symbolizing various crops, farm animals…

The preparation of this bread used to be always accompanied by various rules and rituals all indicating the Pre-Christian origin of this bread: 

The česnica is baked on Christmas Eve or early Christmas morning by the head of household or the woman of the house. The person who will prepare the česnica must bathe before that. In eastern and southern Serbia, after they kneaded the dough for the česnica, the head of household or the woman of the house take hold with dough-stained hands of the fruit trees, beehives, and cattle to make them more fertile.

Dough is usually made with wheat flour. But the flour is taken only from a full sack or the flour is milled from the last sheaf of wheat from the previous harvest. The water for the dough is in some areas collected on Christmas Day before sunrise from a spring or a well, into which a handful of grain is thrown. It is called the “strong water” or “living water” and is believed to be imbued with beneficial power. Or the water for the dough is collected from three springs. 

A coin is put into the dough during the kneading, some families using the same coin from year to year; it may be a valuable piece. In some regions, little figures carved from cornel wood, representing chickens, oxen, cows, swine, bees, and the like, are also put into the dough. In other areas, the inserted objects include grains, broad beans, walnuts, tufts of wool, twigs, and splinters from various wooden buildings. In Semberija, families insert a piece of the first splinter produced in felling the badnjak (young oak tree which is the traditional Serbian Christmas tree). Badnjak is ceremonially burned through Christmas eve on the house fire. In Jadar, western Serbia, the number of embers of the badnjak equal to the sum of grain and livestock sorts grown by the family are taken out of the fire and placed on the česnica. Each of the sorts is associated with its own ember on that loaf. The sort whose ember retains its glow longer than the others should be the most productive in the coming year. In Bosnia, when the dough is shaped and ready for baking, a number of notches are cut in the upper surface of it, and seeds of various crops are placed into the notches. The more a notch has risen when the česnica is baked, the more productive the crop whose seed is in it will be in the following year. To ensure an abundance of grain, some people place a bowl filled with grain on the česnica.

All of this indicates that česnica is directly linked with fertility and particularly grain fertility. 

The word “česnica” could be derived either from the noun “čast” meaning honor, or “čest”, meaning “share”. Both roots describe this bread perfectly. It is a bread made in honor of Dabog, Triglav, the Sky father, the father of grain who was in Christianity replaced with Christ. The bread is also made to be shared. 

In Serbia Christmas dinner is the most festive meal of the year. It begins about noon, or even earlier. The family members seated at the table stand up when the head of household gives a sign. The head makes the Sign of the Cross and lights a candle, before blessing the gathered relatives and saying a prayer, after which they all kiss each other while saying, “Peace of God, Christ Is Born.” The head of the family and another man of the family hold the česnica between themselves, rotating it three times counterclockwise. The fact that česnica is turned three times shows that the bread was originally dedicated to Dabog – Triglav. The counterclockwise rotation of česnica is an example how an old Pre -Christian ceremonies and symbols which could not be eradicated where in Christianity turned into its opposites. Originally česnica must have been turned clockwise, to the right, the way the sun moves across the sky. Making people turn česnica counterclockwise implements magical way of destroying the symbol’s power by either turning it upside-down, or the other-way-round. We see this being used over and over again with Christianized pagan symbols, rituals and beliefs…Anyway, after it is rotated, the česnica is then carefully broken among the relatives, so that each of them gets his own piece of the bread, without a crumb falling off. Bread falling onto the ground, and throwing bread away are still considered a big sin in Serbia. 

Up to three pieces of the loaf may be set aside: one for the absent relatives (if there are such), one for a stranger who might join the family at the dinner, and one for the položajnik (polaznik), their first visitor on Christmas Day (if he is not present). The rest of the česnica is consumed during the dinner. The family member who finds the coin in his piece of the bread will supposedly be exceptionally lucky in the coming year. The head may try to buy the coin from this lucky relative. Each of the other objects hidden in the bread indicates the segment of the household economy in which the person who finds it in his share of the česnica will be especially successful. 

Now remember the giant bread from Saxo’s description of Slavic pagan fertility ritual? They are still made in Serbia too. These are giant communal česnica breads which are ceremonially broken and shared among all the members of the community. Or at least everyone quick enough to get a piece 🙂 

And we have ethnographic evidence that česnica breads were in the past used for the same “peekaboo” grain fertility ritual described by Saxo. 
In his dictionary, Vuk Karadzić says this about the verb “milati”: “I have heard that in Herzegovina people “milaju” at Christmas with česnica (large round flat Christmas bread, cake). This is what they do: Two people take česnica, one of them holds it in front of himself and asks the other: “Milam li se”? meaning “Am I visible? Can you see me? Am I sticking out from behind the cake?” The other man then says: “Milaš malo” meaning “you are visible a little, you are sticking out a little”. The man holding the bread then says “Danas malo a dogodine ni malo” meaning “This year a little, but next year hopefully not at all”. 
Ljubomir Pećo noted the same custom among Croats in the village Zabrđe in Bosnia. 
Similar custom was recorded in Old Serbia. Jastrebov, in “Obыčai i phsni tureckihь Serbovъ. S. Petersburgъ”, 1886, str. 41, upor. i RJA talks about the custom called “milanje”: A househusband hides behind a pile of breads and asks his family: “do you see me?”. The family members reply “We see you this year, but we hope not to see you at all next year”, meaning “We hope the grain harvest next year is so big, and that we can make so many breads, that you can hide completely behind them”. 
In some parts of Old Serbia and Makedonia, the househusband hiding behind the Christmas cake says “You see me now, but may god give such huge ears of wheat this year that you wont see me at all behind them. Sometimes the “milanje” ritual was performed in Serbia at the end of the harvest with newly harvested grain. In the village of Grmljani in Lika near Trebinje this ritual was performed during the threshing of grain on the threshing floor. A pile from newly threshed grain was made on the threshing floor. Two people would stand on the opposite sides of the pile. The first man would then ask the second: “Do you see me?” and the second would answer: “I don’t see you”, to which the first man would reply “May god give that you don’t see me next year either!”
The word “milanje” comes from “maljanje” which comes from “malo” meaning “a little”. So the meaning of “milanje” is “sticking out a little”…
This is a magical ritual which is performed with the intention to give god a hint to make the next years grain crop even bigger. In a way people are trying to trick god, as bread used in the ceremony is never big enough for a person hiding behind it to fully disappear from view, no matter how big the harvest was. 
This custom was also preserved as a a new year or all souls (samhain), end of harvest, thanksgiving tradition in some other Slavic nations. 
Ukrainians and Belarusians have the same custom, except that they use a shief of wheat instead of bread. 
Karpatho Rusyns have the same custom. In the article about Christmas and New Year customs of the Rusynes, written by Mykola Musinka on “carpatho-rusyn.org” we read that most magic customs were connected with Christmas Eve (Svjatyj vecur, Korocun, Vilija). On that day the husbandman covered the floor with straw. An unthreshed grain sheaf, usually oats (called in some localities “Didko” or “Diduch” meaning grandfather), was placed on the honorable seat at the table, i.e., “into the corner” under the icons. According to historical and ethnographic literature, in the archaic Slavic homes one corner was reserved for a representation of the pagan gods. Oats or straw were also used for decorating the festive table on which there had to be seeds from all crops. In the spring these very seeds were used in the first sowing. The oats and straw had a magical function in pagan society: they were expected to secure plenty of fodder and grain. Christianity provided another rationalization for the custom, stressing the birth of Jesus on straw and oats, thus transforming the two into symbols of that event. Also placed in the place of honor was the festive bread (korocun, kracun) decorated with wintergreen or periwinkle (barvinok) and various small figures. Prosperity was symbolized by a “mountain” of bread at the end of the table. At the beginning of the evening meal the husbandman hid behind this “mountain,” asking: “Can you see me from behind the bread mountain?” The children replied in a chorus: “We can’t,” after which the husbandman concluded: “Let us wish you’ll not see me either in the spring from within the hay or in the summer from within the wheat!”
So lets recapitulate. 
Serbs are people whose main deity was once Dabog (giving god) also known as Hromi Daba, and Triglav (the three headed one). They have a special votive bread called “česnica” which they bake for Christmas, the Christianised Winter Solstice, the end of the solar year. They use this bread for magic ritual related to fertility and good fortune. The bread is round made from sweet dough. A coin is put into the dough during the kneading. In some regions, little figures carved from cornel wood, representing chickens, oxen, cows, swine, bees, and the like, are also put into the dough. In other areas, the inserted objects include grains, broad beans, walnuts, tufts of wool, twigs, and Christmas tree splinters… The bread is broken by family or community members and consumed during the Christmas dinner. The family member who finds the coin in his piece of the bread will supposedly be exceptionally lucky in the coming year. Each of the other objects hidden in the bread indicates the segment of the household economy in which the person who finds it in his share of the votive will be especially successful. This bread seams to have also been made at the beginning of November, for the thanksgiving ceremony marking the end of the harvest and the end of the agricultural and vegetative year. Saxo Gramaticus in the 12th century mentions this bread as the votive bread made by Pagan Slavic tribe known as Rujani, (red, redhead people???)  who lived on an island of Rujan (red, redhead people???) island, which lies just of the coast of South Baltic, which Slavs call Pomorje meaning seaside. People from Pomorje are known as Pomori, Pomorci. 
Now this is very interesting because:
The Irish are people whose main deity was once Dadga (giving god) who is believed to be another name of Crom Dubh, and who is possibly the god who was represented by three headed idol found in Ireland. The Irish have a special votive bread called Barmbrack which is today made for Halloween, Christianised Samhain. Samhain, which was originally celebrated at the beginning of November, was the thanksgiving ceremony marking the end of the harvest and the end of the agricultural and vegetative year. Barmbrack  traditionally contained various objects baked into the bread and was used as a sort of fortune-telling game. In the barmbrack were: a pea, a stick, a piece of cloth, a small coin (originally a silver sixpence) and a ring. Each item, when received in the slice, was supposed to carry a meaning to the person concerned: the pea, the person would not marry that year; the stick, would have an unhappy marriage or continually be in disputes; the cloth or rag, would have bad luck or be poor; the coin, would enjoy good fortune or be rich; and the ring, would be wed within the year. Samhain was also the time when Fomorians extract their taxes of corn, milk and live children. Fomorians were an evil race of people who came from across the sea and their name is said to mean “sea (seaside???) people”. Samhain is also the time when the Irish sacrificed first fruit, including first born children, to the evil god Crom Cruach (Crom Dubh). Samhain was also the time when a demon known as Aillén Tréchenn (from trí ceann, three-headed) came from Cruachan in Roscommon, and caused havoc in all of Ireland, especially Emain Macha (Armagh) and Tara.  O and in Irish the word “rua” means red-haired person. 
Do you think that this is all a coincidence? Or maybe there is some kind of connection here? 
But the best part is still to come: 
The etymology of the word “barmbrack”. In Ireland “barmbrack” is sometimes called “Bairín Breac”, and the term is also used as two words in its more common version. The official translation of “Bairín Breac” is 
bairín – a loaf – and breac – speckled (due to the raisins in it), hence it means a speckled loaf, a similar etymology to the Welsh “bara brith”. Bara brith comes from Welsh “bara” meaning bread and “brith” translating as speckled”
But this Welsh name could just be a direct transliteration of the Irish Bairín Breac. The Irish Laigin, who gave their name to the province of Leinster, used to rule the north Wales Llŷn Peninsula, which was named after them. So I believe that they might have brought this bread and the name with them. 
But that is beside the point. The important bit is that I don’t think that the translation of the “Bairín Breac” as “speckled bread” is correct. Sure now raisins are added to the dough, but I don’t think that the ancient Irish had access to grapes and raisins. I believe that this is a recent addition to the recipe and that originally the “Bairín Breac” was made from plain sweat leavened dough. I believe that the correct translation for “Bairín Breac” is patterned bread, bread which has patterns inscribed on it. Why? Because believe or not the word “breac“, apart from meaning speckled, which by the way also means patterned, has another very interesting meaning: carve, engrave, mark with letters, figures, to write…Now this is most interesting because it perfectly describes “česnica” which is always marked with letters, figures, patterns…Decorating of special votive breads with patterns has been practiced in the Balkans since early Neolithic. Special bread stamps were developed for stamping breads probably to standardize and make easier the inscription of the religious patterns used by all the members of the community. Some of the patterns and patterned stamps actually haven’t changed since neolithic and are still used on votive breads today. 
Vinča culture was one of the cultures which decorated their breads with patterns and which had bread stamps and votive breads. I mentioned one of these votive breads in my post about Newgrange, because a giant stone copy of the small Vinčan clay votive bread stands in front of the entrance into Newgrange. 
This is small Vinča votive clay bread:

This is giant Newgrange votive stone bread:
Both of these votive breads are decorated, inscribed with patterns and symbols. Both of them are “Bairín Breac”. Both of them are “česnica” breads. 
Now remember the Redhead Rujani people from South Baltic. On Samhain, they would bring a giant, inscribed, patterned česnica bread in front of the temple entrance, and the priest would hide behind it and would ask his people: “Do you see me”? Serbs performed the same ritual on Christmas day, the Christian replacement for Winter Solstice. 
Newgrange tumulus is aligned with the sunrise on the Winter Solstice so originally it was probably used for ceremonies on Winter solstice morning, beginning of the new Solar year. However Irish tradition strongly associates Newgrange with Samhain, so it is possible that the original alignment and use of Newgrange was over time forgotten and the date on which Newgrange was used for ceremonies shifted from Winter Solstice, the beginning of the new Solar year to Samhain evening, the beginning of the new Agricultural year. Regardless of how and when Newgrange was used for ceremonies, I believe that Newgrange was used as the temple of the divine marriage of Heaven and Earth, the marriage which produces grain, bread. Hopefully lots and lots of big breads, as big as the votive stone bread standing in front of the tumulus entrance. Or bigger. So is it possible that similar to the Slavic tradition, a pagan priest would come out of the Newgrange tumulus on Summer Solstice or Samhain, stand behind the giant votive stone bread and ask his people: “Do you see me?”. 
Well we will never know, but… 
Sources for “milanje” ritual in the Balkans:
Српски рjечник, истолкован њемачким и латинским риjечма” Вук Стефановић Караџић (Dictionary of Serbian language by Vuk Stefanovic Karadzic)
Srpski Mitoloski Recnik – Grupa Autora” (Serbian mythological dictionary)
Stara slovenska religija u svjetlu novijih istraživanja posebno balkanoloških” – Akademija nauka i umjetnosti Bosne i Hercegovine, 1979
Christmas in Croatia” by Dunja Rihtman-Auguštin
“Kalendar srpskih narodnih obicaja” by Mile Nedeljkovic. Not available online


This is Newgrange, a prehistoric monument in County Meath, Ireland, located about one kilometre north of the River Boyne. It was built about 3200 BC. Newgrange is a large circular mound (tumulus) with a stone passageway and chambers inside. The mound has a retaining wall at the front and is ringed by ‘kerbstones’ engraved with artwork. There is no agreement about what the site was used for, but it has been speculated that it had religious significance.

Once a year, at the winter solstice, the rising sun shines directly along the long passage, illuminating the inner chamber.

This illumination lasts for about 17 minutes. The sunlight enters the passage through a specially contrived opening, known as a roofbox, directly above the main entrance. Solar alignments are not uncommon among these so called “passage graves”. Which makes you wonder if they were graves at all or maybe temples where distinguished and important people also got buried, in the same way distinguished and important people were buried in cathedrals and churches… Anyway, Newgrange is one of few of these tumuluses with solar alignment to contain the additional roofbox feature; Cairn G at Carrowkeel Megalithic complex is another, and it has been suggested that one can be found at Bryn Celli Ddu. The alignment is such that although the roofbox is above the passage entrance, the light hits the floor of the inner chamber. This is because the entrance corridor is built in such a way that it climbs upwards towards the main chamber.

Today the first light enters about four minutes after sunrise, but calculations based on the precession of the Earth show that 5,000 years ago first light would have entered exactly at sunrise.

Every year on winter solstice morning, hundreds of people gather to whiteness this event. And today, the 21st of December 2016 is no different. Except that hundreds of people who gathered in front of Newgrange today are going to be pretty pissed off. It’s pissing with rain and the sky is covered with thick clouds, so it is unlikely the sunlight will enter the chamber today.

Why did our ancestors build Newgrange the way they did?

The whole construction of the Newgrange tumulus indicates that it was constructed as a shrine dedicated to the holy union between father sky and mother earth. The tumulus is shaped like a pregnant woman’s belly. The inside of the tumulus resembles female reproductive organs. 

The door (vulva, vaginal opening) leads into a long narrow passage (vagina and cervix) which climbs upwards and eventually opens up into corbelled, domed chamber (uterus) with three side chambers. Each of the smaller chambers has a large flat “basin stone”. The tow side ones (ovaries) and the top one (fundus). The fundus, the topmost portion of the uterus and is known as the roof of the uterine cavity. During pregnancy, this is usually when the fertilized egg implants. 

And guess what the sun rays hit then they penetrate the inside of the tumulus? The bawl located in the top chamber, the fundus….

On top of this the entrance is shaped like a penis, with the roofbox, or better lightbox, being the head of the penis:
Just in case you didn’t get the hint yet 🙂
Anyway, the sun rays entering the main chamber deep inside the earthen mound and hitting the bawl in the fundus is literally copulation, intercourse between the father sky and mother earth. The fact that Newgrange was aligned with the sunrise on the Winter Solstice, allows the young father sky to penetrate mother earth on the first day of the new solar year, and thus ensure the mother earth’s fertility. The whole construction was designed to help young father sky “find the way”considering that he was just born, and lacks experience and practice… 🙂  I believe that the idea was that once the young father sky did it once, he will not be able to stop and will keep at it for the rest of the year….Because it is this copulation, intercourse between the father sky and mother earth which produces all life on earth. 

And bread…Which is really why people bothered making Newgrange. They needed grain, and without father sky getting mother earth hot and bothered and pregnant, there will be no grain and no bread…And this brings me to the mysterious stone that stands in front of the main entrance of the Newgrange tumulus. 

This is Newgrange entrance before excavation and renovation. You can clearly see the carved stone standing in front of the entrance. 

This is what Newgrange entrance looks like now. The carved stone is still standing in front of the entrance into the tumulus. 

Why is this stone placed in front of the entrance and what does this stone represent?

I believe that this stone is a huge votive bread. It is placed in front of the entrance of the tumulus, because this entrance represents vulva and vaginal opening of the mother earth. As I said I believe that Newgrange was designed to represent pregnant mother earth in a shape of a pregnant woman’s belly together with reproductive organs. And as pregnant women give birth to babies through the vaginal opening, to continue with the symbolism, this votive bread was placed in front of the entrance (which is in this case viewed as exit) to symbolise mother earth giving birth to bread. And to give mother earth a hint how much bread we want her to give birth to. A lot.

Why do I think that this stone represents votive bread. Well have a look at these two pictures:

Entrance stone, with carved diamond and spiral ornaments, Newgrange, Ireland, 4th millennium BC:

Ritual clay votive bread with carved diamond and spiral ornaments, Potporanj – Kremenjak, Serbia, Vinča culture, 5th millennium BC, currently in Vršac museum. Quite a few of these ritual clay breads were found in Vinča sites, and they all have these types of decorations: 

See any similarity? 
Now remember my article “Clay balls – Stone balls“? 

In it I talked about the possibility that the origin of the Scottish so called “stone carved balls” could be found in the clay amulets from Serbia. And clay amulets found in the Boyne valley, and dated to the same period as Newgrange and which are almost identical to the the ones from Vinča sites…
At the end of the article I said that the carved balls were not the only type of artefacts which were first found in Vinča cultural layers in the Balkans, small and made of burned clay, only to be found later in Britain much larger and made of stones. Progressively bigger and bigger stones. 
This is another example. A small votive clay bread from Vinča culture became a huge votive stone bread. But the message stayed the same:
Holy mother and father give us this day our daily bread….A lot of it….
It looks like the British Megalithic culture could be in a way the continuation of the Vinča culture. Vinča culture which somehow got to Britain and there went Megalomaniac and Megalithic. 
What do you think about all this?

Fulacht fiadh – sweat lodge?

Some fulacht fiadh reconstructions, such as the one at Ballyvourney, include circular, hut-type structures based on the post holes found at the sites. One theory is that these small buildings on site were used as sweat houses. This theory was based on:

1. In Irish legends, Fulachta Fiadh were not just described as “the cooking place of the Fianna” (Fianna – small, semi-independent warrior bands in Irish mythology). They were also said to have been used by Fianna for bathing. 

2. Ireland has a very long tradition of sweat houses which are in Ireland called “Tigh ‘n Alluis” meaning houses of sweat.

Traditionally the Tigh ‘n Alluis was built in the form of beehive huts made of dry-stone walls covered in clay and turf, with seats within which were covered with straw or grassy sods upon which the subject sat or lay. It usually had a small opening in the roof and a low doorway, both were covered by flag-stones when the subjects were inside.

The Sweat House was heated by a variety of means, most commonly by igniting a large peat fire in the hut’s centre and clearing the ashes before entering. The fire would heat the stone walls which would then radiate the heat towards the inside of the hut. Another method was by heating bricks, which were carried into the house in a creel in which herbs had been placed, especially when inhalation was a part of the cure.

This description of the use of sweat houses is taken from ‘Traces of the Elder Faiths of Ireland’ by W.G. Wood-Martin:

When men used it as many as six or eight stripped off and went in, when all openings were closed except what afforded a little ventilation. A person remained outside to attend to these matters. When they could suffer the heat no longer, the flag was removed, and they came out and plunged in a pool of water within a yard or two of the sweat-house, where they washed, got well-rubbed and put on their clothes. In case of women, they put on a bathing dress whilst using the bath, and generally omitted the plunge…

Another description of the Gaelic sweat houses and their use can be found in the book “A smaller social history of ancient Ireland, treating of the government, military system, and law; religion, learning, and art; trades, industries, and commerce; manners, customs, and domestic life, of the ancient Irish people” by Joyce, P. W. (Patrick Weston):

The hot-air or vapour bath was well known in Ireland, and was used as a cure for rheumatism down to a few years ago. It was probably in use from old times; and the masonry of the Inishmurray sweating-house, represented opposite, has all the appearance—as Mr. Wakeman remarks—of being as old as any of the other primitive buildings in the island. The structures in which these baths were given are known by the name of Tigh ‘n alluis [Teenollish], ‘sweating-house’ (allus, ‘sweat’). They are still well known in the northern parts of Ireland—small houses, entirely of stone, from five to seven feet long inside, with a low little door through which one must creep: always placed remote from habitations: and near by is commonly a pool or tank of water four or five feet deep. They were used in this way. A great fire of turf was kindled inside till the house became heated like an oven; after which the embers and ashes were swept out, and water was splashed on the stones, which produced a thick warm vapour. Then the person, wrapping himself in a blanket, crept in and sat down on a bench of sods, after which the door was closed up. He remained there an hour or so till he was in a profuse perspiration: and then creeping out, plunged right into the cold water, after emerging from which he was well rubbed till he became warm. After several baths at intervals of some days he commonly got cured. Persons are still living who used these baths or saw them used.

Knowing this, it easy to see how the theory that the fulachta fiadh were used as sweat houses – baths could have sprang forward.

In the “Cois tSiuire – Nine Thousand years of Human Activity in the Lower Suir Valley” by Eogan, J. and Shee Twohig we can see this reconstruction of a Fulacht fiadh used as a sweat house.

On the above artist’s depiction of a fulacht fiadh used as a sweat house, you can see the low domed yurt type hut full of people. On the left if the hearth where stones are heated. These stones are then brought into the hut to create heat. In front of the hut is the through used as a plunge pool. Again I have to repeat, that only throughs cut into a well drained dry soil, or into the reiver bank or a beach could have been used as plunge pools. It is quite possible that the fulacht fiadh through found on the Coney island could have been used as a bath.

You definitely don’t want to lay into a through cut into a marshy boggy soil which is full of acidic bog water…

Anyway, the hut on the above depiction of the fulacht fiadh looks very much like the “inipi” sweat house used by Native American.

This is a short instruction how to build this type of sweat lodge hut.

Building the “inipi” sweat lodge frame

The average sweat lodge hut has a diameter of about 9 feet. This is why. You need to dig a pit two feet in diameter in the center of the lodge. This is where the hot rocks are placed to heat the hut. You then need to be able to sit cross legged facing the hot rocks at about 2 feet from the rocks. Add about 5 feet for sitting area, enough for a person sitting cross legged leaning against the wall. You end up with 9 feet.

Use a short sharpened stick and stick it into the ground. This is the center of your hut. Attach a string to it. Stretch the string two feet from the stick. Attach another smaller sharpened stick (drawing stick) to the string and draw a circle two feet in diameter. This is where the hot rock pit will be dug later. Stretch the string another 5 feet. Reattach the drawing stick to the string and draw a circle 9 feet in diameter. This is where the hut wall will go. A nine foot diameter lodge will seat twelve people comfortably.

The frame can be made from willow or hazel, but any sapling will do. You need about 12 saplings with about two inches in diameter each. After the saplings are cut, the branches need to be removed and the bottoms need to be sharpened. Stick the sharpened ends into the ground at an equal distance around the drawn outer wall circle, leaving an opening for the doorway. You have to make sure the saplings are embedded deep enough into the ground so they hold firm when they are bent and tied together to form the domed frame. The bend of the sapling should allow for a large man to sit comfortably. Don’t build your lodge too tall or it will be difficult to heat. Bind the opposite saplings together to form arches and then tie the arches together to form a dome. To strengthen and reinforce the hut structure, weave sapling horizontally between the upright saplings and tie them together. The procedure is as if you are building a large upturned basket.

Covering the “inipi” sweat lodge

Originally the Native American sweat lodge huts were covered with hides, then blankets and then with hides again. This combination of materials provides both thermal insulation and is water resistant. Today you can use any combination of the materials with the same characteristics: plastic sheets, tarps, blankets…

The bottoms of the covers should lay on the ground for about a foot. Pile rocks on the bottoms, all around the sweat lodge. This is to seal the bottom up from drafts. You can make the door from several folded blankets wider than the opening.

Using the “inipi” sweat lodge

In order to turn the hut into a sweat lodge, you need red hot rocks. For the 9 feed diameter hut probably about 20 – 30 red hot rocks. Rocks are heated on the pyre burning in the fire pit which should be built facing the hut entrance. Like this one in the picture below.

The sides of the fire pit are covered with the rocks from previous sweats. They are not reused because most get pretty cracked. As the fire pit is cleaned for the next heating of the stones, the ashes and coals are swept on the sides of the fire pit. Then the stones from the last sweat get piled on top. This results in the creation of a U shape burned mound just like the burned mounds in fulachta fiadh.

When the rocks are red hot, they are dragged into the hut using long forked sticks or carried using into the hut using a long handled pitchfork. There they are pushed into the hut’s rock pit which is positioned in the center of the hut.

Once the rock pit is full of hot stones, people sit inside the hut around the stones and the entrance is covered with blankets. As the temperature inside the hut rises, people will begin to sweat. Water can be splashed over the hot rocks to produce steam and turn the hut from sauna into a steam room.

It is very important to note that the Native American sweat lodges are temporary structures which once dismantled would leave very little to no footprint, apart from the burned stones and hearths used for their heating. Add the through used as a plunge pool and you have the fulacht fiadh…

Also these sweat lodges can be made by a small group of people in several hours. Fianna, the people who supposedly build fulacha fiadh (or as they are also known fulachta fian) were in the Irish legends small, semi-independent warrior bands. It is believed that they are based on historical bands of landless young men in early medieval Ireland known as kerns. Geoffrey Keating, in his 17th-century History of Ireland, says that during the winter the fianna were quartered and fed by the nobility, during which time they would keep order on their behalf, but during the summer, from Beltaine to Samhain, they were obliged to live by hunting for food and for pelts to sell.

So these hunting bands would set into the wilderness in May and would, once reaching their hunting grounds, need a place to rest, recuperate, clean up. And the “inipi” type sweat lodge plus a through serving as a plunge pool or a bath is easy and quick to make and run and is ideal for a hunting party which stays in one place for a week and then moves on. These hunting parties probably moved following rivers as the easiest ways to travel through thick forests. And they would probably follow the same route through their hunting grounds every year, camping at the same camp grounds and reusing the old sweat lodges year after year. After several years the amount of burned stones would accumulate to the point where we would see appearance of characteristic “burned mounds”.

Now what is interesting to note that the Native Americans who built “inipi” sweat lodges, used exactly the same technique to build their lodgings, huts used for living. The Native Americans called these types of huts wigwam, wickiup or wetu.

This type of domed, round shelter was used by many different Native American cultures. 
This is Apache wickiup
This is Ojibwe wigwam
These videos show how to make a wigwam using primitive tools:
The rock pit in the center of the inipi sweat lodge became a fireplace in the center of the wigwam. The seating area along the wall used for sitting in the inipi sweat lodge, became sitting and sleeping area in the wigwam.  
What is very interesting is that some Irish archaeologists suggested that the Irish round houses didn’t, as is commonly accepted, look like this:
 but that they were actually wigwam shaped domed structures. 

Here is a reconstructing a Late Bronze Age dwelling based on the continuous beehive basket weave method put forward by Damien Goodburn of the museum of London.
The layout of the dwelling is based on structure 12 which was excavated during the Ballyhoura hills project in Ireland. The basket walls were made from hazel coppice, young offshoots of the hazel tree which are ideal for basket weaving and are with willow coppice the best material for making baskets. To finish the shelter, you would proceed by covering the basket frame with some kind of waterproof material. 

But basically they could have been just build using the above described wigwam construction technique, which is identical to the the technique used for making sweat lodges, which is the same technique used for making wigwams. 
Please note how these huts look almost identical in shape to the “Tigh ‘n Alluis” Irish sweat houses just made from different material….
Now interestingly the translation of “inipi” is actually not “sweat lodge”. The actual translation is “The way we live” or “We live” or “A shelter which can be both a sweat lodge and a spiritual place and a lodging and a living place….”.
Remember how fulacht fiadh were also called fulacht fían? Well the word fían does mean “a warrior” and “a hunter” and “hunt” but the word fían also means “bedding, cover” and “a hunting-bothy“, “a hut made of branches or similar construction in a forest or wild spot, an improvised shelter”.
Maybe something like this Mesolithic Ertebolle culture hunters hut perhaps?
Maybe Fiana hunting camp looked something like this:
It’s easy to make, functional shelter used world over for millenniums…
Regardless what the permanent Irish bronze age houses looked like, is it possible that the hunter warrior gangs, like Fianna, built fulacha fiadh as their temporary campaign camps, consisting of a group of wigwam type huts plus a through, plus pit ovens? We have seen that these types of shelters are extremely easy to make. And that once built they could be used as lodgings, storage rooms and sweat lodges. Everything hunters and warriors on the campaign need in a camp. We also saw that these huts can be heated by fire-heated stones or hearths. And that once dismantled, they would leave very little trace behind except for hearths and mounds of burned stones. 
Is this what fulachta fiadh were? 
Interestingly, there is a place in Europe where we still find a particular type of temporary shelters which are built by soldiers, hunters and travelers on campaigns, which are very similar in construction to wigwams or inipis, which are heated by fire heated stones, and which are used as sweat and steam rooms…A permanent version of this temporary shelter was until very recently used both as a dwelling and as sweat and steam room. 
I will talk about this in my next post.

Fulacht fiadh – salt extraction facility?

There is more salt in animal tissues such as meat, blood and milk, than there is in plant tissues. Nomads who subsist on their flocks and herds do not eat salt with their food, but agriculturalists, feeding mainly on cereals and vegetable matter, need to supplement their diet with salt. However the primary attraction of salt in history and prehistory is its use as a preservative. The application of salt to organic material absorbs moisture, inhibiting the growth of bacteria and mold. That fact allowed societies to mass produce food and store it for lean times–a crucial piece of social engineering that made long-term survival through winters and droughts a possibility.

As population grew and the need for better and longer food preservation grew, the value of salt grew too. Eventually, salt became one of the world’s main trading commodities. It is not surprising then that people were willing to put considerable effort into obtaining salt and that salt production was one of the first human activities performed on industrial scale.

You can read more about the role salt played in history in “Archaeology of salt – approaching an invisible past“.

On an industrial scale salt is produced in one of two principal ways: by mining rock salt and by extracting of salt through evaporation of salty water (brine).

Mining rock salt

Before the advent of the internal combustion engine and earth moving equipment, mining salt was one of the most expensive and dangerous of operations, due to rapid dehydration caused by constant contact with the salt (both in the mine passages and scattered in the air as salt dust), among other problems borne of accidental excessive sodium intake. While salt is now plentiful, until the Industrial Revolution it was difficult to come by, and salt mining was often done by slave or prison labor and life expectancy among those sentenced was low. Even as recently as the 20th century, salt mining as a form of punishment was enforced in the Soviet Union and Nazi Germany.

The title “the world’s oldest known salt mine”, is currently held by Hallstatt in the Salzkammergut region of Upper Austria. This is based on the discovery of a pick, made of stag horn and dated to 5000 BC, which was presumably used to mine salt. However we really have no proof of any mining going on in the area until about 1500 BC. This is when we find the oldest concrete proof of an organised mining operation. The salt has been mined in the Hallstatt region ever since.

The actual oldest salt mine in the world is actually located in Azerbaijan. Archeologists have recently shown that the Duzdagi salt deposits, situated in the Araxes Valley in Azerbaijan, were already being exploited from the second half of the 5th millennium BC. This is the most ancient exploitation of rock salt attested to date. And, it seems that intensive salt production was carried out in this mine at least as early as 3500 BC.

Salt extraction from salty water through evaporation

Evaporation can either be solar evaporation or evaporation through boiling.

Solar evaporation

In the correct climate (one for which the ratio of evaporation to rainfall is suitably high) it is possible to use solar evaporation of sea water to produce salt. Brine is evaporated in a linked set of ponds until the solution is sufficiently concentrated by the final pond that the salt crystallizes on the pond’s floor.

Evaporation through boiling

One of the traditional methods of salt production in more temperate climates is using boiling in open pans. In open pan salt works, brine is heated in large, shallow open pans. Brine was poured into the pans, and concentrated by the heat of the fire burning underneath. As crystals of salt formed these would be raked out and more brine added. Earliest examples date back to prehistoric times and the pans were made of ceramics known as briquetage, or lead. Later examples were made from iron. This change coincided with a change from wood to coal for the purpose of heating the brine.

In addition to the above means of extraction, in many parts of the world salt was also extracted from plants.

In North and South America and West Africa salt was extracted from palms through burning.

In Japan, moshio salt which is beige in color and has a nice, rich taste, is made from seaweed. The very earliest method of obtaining salt from seawheed was probably burning seaweed and using the resulting ashes for their salt content. The first challenge in salt-making through boiling sea water has always been to find a way to concentrate sea water, which contains only 3 percent salt. So another method of extracting salt from seaweed seems to have involved collecting seaweed and allowing it to dry in the sun until salt crystals formed. The crystals were then washed off into vats of sea water, creating a concentrated brine that could be boiled down to yield salt.

In modern New Guinea, salt is extracted from plants which have been steeped in brine from salt springs. After soaking plant leaves for three or four days, firewood is used to build a square pyre and is set alight. The soaked leaves are stacked on the pyre, and the fire is kept going from the afternoon until the morning of the next day. The result is a large pile of charcoal, ashes, and salt concretions. The salt is picked out and placed on a large wooden platter, then pressed into a rectangular mold, kneaded with brine, compressed, and wrapped. The salt is further dried over a hearth for a week, which forms a “salt stone” or compact block of salt.

In the article “Extracting Salt from Distichlis spicata (seashore saltgrass): Continued Investigations into Methods of. Salt Extraction and Salt Utilization in Prehistoric California” we can read that:

Distichlis spicata

Many California tribes extracted salt from plants.

Various plants such as Distichlis spicata (seashore saltgrass), Petasites frigidus (sweet coltsfoot), Umbelliferae (Celery) were burned to create salty ashes which were then used as salt.
In some regions salt grass was burned on a grating of hardwood sticks which was laid over a pit full of hot coals. The salty sap oozed out of the plants and dropped on the coals, forming lumps which were extracted from ashes after the pit was cooled.
 Another way of extracting salt from salt grass was by drying it on flat rocks and pounding it in mortar holes. The crushed bits were then winnowed using a circular tray which separated the salt from the grass. The resulting salt was then dampened and pressed into balls. The balls were broken as needed for use.
In some cases, the salty plants were were eaten raw.
Sometimes non saline grass was soaked in brackish water and then burned.

In the article “Evidence for medieval salt-making by burning Eel-grass (Zostera marina L.) in the Netherlands” we read that during the medieval time in the area of Zealand, the peat from reclaimed land was cut and used for fuel, but due to the high salinity of the peat was also used for salt-making. For the purpose of salt-making, at low tides the clay layer was dug away and the salt-impregnated peat layers were cut into bricks. These were then dried in the wind and burned on the spot. Next, the ashes were gathered and brought to salt sheds (boiling huts), mostly located near towns or villages. In the sheds, the ash was plunged into large drums, preferably filled up with salt water to increase the salt content of the brine, and subsequently heated to evaporate the water. When the peat deposits were exhausted, eel grass was use instead of salty peat for concentration of brine used in salt making.

Marine eelgrass

In the article “London Gateway: Iron Age and Roman Salt Making in the Thames Estuary” we can read that Stanford Wharf Nature Reserve area in Themes valley was during the middle Iron Age (c 400-100 BC) a very important center of salt making. Excavation across the north-western corner of Area A uncovered the remains of red hills, a characteristic feature of long-term salt production on the Essex coast. Other evidence relating to salt production included pits, hearths and briquetage, a coarse ceramic used for making salt-processing equipment, such as cylindrical moulds, troughs, pedestals and firebars. The site continued to be used until late Roman period. The analysis of the content of the red hills revealed that they consisted of fuel ash derived from burnt salt marsh plants and sediment (peat). The plants, harvested still with marsh sediment adhering, were dried and burnt as fuel for hearths, above which brine was evaporated to crystallise salt. A by-product of the fuel burning was a salt-rich ash, which when mixed with seawater, was turned into a highly saline solution. This was filtered, and the resulting brine was then also evaporated above salt marsh plant-fuelled hearths. It was the residue from hearths and filtering that was dumped to create low mounds or red hills.

Strabo reports further methods of brine concentration and salt extraction by European tribes to include  ‘flinging’ or ‘dowsing’ salt brine over hot stones and then collecting and scraping the salt crusts from the stone. “A surprisingly quick process…” The stones were certainly fractured due to the heat gradient in such methods as were the crude sherds found at the red hills.

Another method, used in Gaul and Germany, included dripping brine on to glowing charcoals and using the resulting ash as salt. You can read more about this in “Studies in ancient technology volume III” By R. J. Forbse. The same method was recorded in Philippines and you can read about it in the article “Documenting Bohol’s traditional method of salt production and the importance of salt in the region’s early economy“.

Knowing how valuable the salt was it is also not surprising that large communities grew around sources of salt, and along the salt trading routes. 

The oldest industrial scale salt-works operation in Europe has been discovered at the Poiana Slatinei archaeological site next to a salt spring in Lunca, Neamț County, Romania. Evidence indicates that Neolithic people of the Precucuteni Culture were boiling the salt-laden spring water through the process of briquetage to extract the salt as far back as 6050 BC. The salt extracted from this operation may have had a direct correlation to the rapid growth of this society’s population soon after its initial production began. The remnants of this salt extraction facility today are giant burned mounds consisting of broken salt extraction pottery and ash.

Salt production was very lucrative. No wonder then that what is now thought to have been the first city in Europe Solnitsata, in Bulgaria, was built next to a salt mine, which provided the area now known as the Balkans with salt since 5400 BC. Even the name Solnisata means “salt works”.

In the article “Neolithic flat-based pots from the Carnac Mounds in the light of Cycladic ‘frying pans’“, we can read about a rare type of pottery, found in four single graves under earthen mounds in the Carnac region of Brittany, and dated to 4600–4200 BC. These vessels are circular, flat-based and with a near-vertical wall. The authors of the article suggest that based on the salt extraction equipment known from elsewhere in the world, it is possible that these dishes too were used for extraction of salt from sea water. The results of experiments using replicas of these dishes demonstrated that these  vessels could have been heated and used to boil brine in the same manner as their ethnographic counterparts.

The same method of salt extraction from sea water was used In England during Bronze Age, Iron Age and into the Roman period. The remnants of these salt works are today known as Red hills.

Red Hill is an archaeological term for a small mound with a reddish colour found in the coastal and tidal river areas of East Anglia and Essex. Red Hills are formed as a result of generations of salt making, deriving their colour from the rubble of clay vessels made from briquetage and used in the salt-making process that have been scorched red by fires used to evaporate sea water to make salt cakes. Briquetage is also known as Very Coarse Pottery or VCP.

These sites contained large water settling pits, where water was left to rest for a period of time to allow impurities to settle to the bottom. The water was then poured into clay pans which were heated over the fire until the water became concentrated enough for salt crystals to start forming. The concentrated salty water (brine) was then poured int crystallization cups. These were then also heated over fire. As the water evaporated the salt crystals would form and settle at the bottom of the vessel. Concentrated salted water (brine) was added to the cups continuously and evaporated until the salt crystals filled most of the vessel. The remaining water was then evaporated and the salt in the cup was dried until it became rock hard. The cup was then broken and the containing “salt cake” was taken out.

You can read more about this in the book “THE RED HILLS OF ESSEX: Salt-Making in Antiquity” by Fawn, A J, Evans, K A, McMaster, I: Davies, G M R

The same or very similar way of extracting salt from sea water was still used in Britain in the 17th century. In her book “Through England on a side saddle” Celia Fiennes describes salt works she saw near Limington.

The seawater they draw into trenches and so into several ponds that are secured in the bottom to retain it, and it stands in the sun to exhale the watery part of it, and if it prove a dry summer they make the best and most salt, for the rain spoils the ponds by weakening the salt.

When they think its fit to boil they draw off the water from the ponds by pipes which conveys it into a house full of large square iron and copper pans; they are shallow but they are a yard or two if not more square, these are fixed in rows one by another it may be twenty on a side, in a house under which is the furnace that burns fiercely to keep these pans boiling apace, and as it candy’s about the edges or bottom so they shovel it up and fill it in great baskets and so the thinner part runs through on moulds they set to catch it, which they call salt cakes’.

The rest in the baskets dry and is very good salt and as fast as they shovel the boiling salt out of the pans they do replenish it with more of their salt water in their pipes. They told me when the season was dry and so the salt water in its prime they could make 60 quarters of salt in one of those pans which they constantly attend night and day all the while the fire is in the furnace, because it would burn to waste and spoil the pans which by their constant use wants often to be repaired. They leave off saturday night and let out the fire and so begin and kindle their fire Monday morning, its a pretty charge to light the fire.

Their season for making salt is not above 4 or 5 months in the year and that is only in a dry summer. These houses have above 20 some 30 more of these pans in them, they are made of copper.

They are very careful to keep their ponds well secured and mended by good clay and gravel in the bottom and sides and so by sluices they fill them out of the sea at high-tides and so conveyed from pond to pond till fit to boil“.

Now what about Ireland? How did ancient Irish get their salt? 

Well we have no idea what the Bronze Age and Iron Age Irish relationship with salt was, but we can presume that that like everyone else in the world, they also used and highly appreciated salt. The situation is a bit better when we come to the medieval time as there are a lot of mentions of salt in Irish medieval manuscripts.

In the “A History of Irish Cuisine (Before and After the Potato)“, we can read that the medieval Irish used salt for seasoning food but also for preserving meat and fish.

The Senchus Mór mentions salt as one of the important articles in the house of a brewy, on which the glossator remarks that it is “an article of necessity at all times, a thing which everyone desires.” It was kept in lumps or in coarse grains; and at dinner each person was served with as much as he needed.

The Críth Gablach mentions salt meat as part of the sick maintenance given to a noble if he is unlawfully injured by another party. You can read more about this on this page of the “Early Medieval Irish Túath” web site.

In the Bretha Crólige, the druid is considered as having the same sick-maintenance as a bóaire, which entitles them to salt meat on his dish every Sunday, as well as extra if they have more property. You can read more about this on this page of the “Early Medieval Irish Túath” web site.

In the “Papers read for the Royal Irish Academy by MacNeill, John, 1867-1945” we can read that the 8th century text Conall Corc and the Corco Luigde records that the Aran Islands paid a tribute of salt to the King of Cashel, their overload.

In the “Irish Hagiographies as Tools for Conversion” we can read that in Saint Columba’s hagiography which was written in the 7th century, Adomnán tells of an instance where Columba had blessed a salt block and given it to a family, who in turn hung it on their wall. The village later burned down, destroying everything except the small section of wall from which the block hung.

And so on and so forth…

But even though we know that the medieval Irish loved and valued salt, we have no clue how they obtained it. Now I can hear people saying: Ireland is an ISLAND in a SALTY sea…Wouldn’t it be logical that they got their salt from the sea?

Well sea water was probably the source of the salt used in Ireland. Even though Ireland has huge rock salt resources they were not discovered until 19th century. These rock salt deposits were discovered by people who were exploring for coal and metals and were located deep under ground, quite out of reach of people with primitive mining equipment. One location where there has been (and remains) a large volume of rock salt is at Kilroot, near Carrickfergus in Co. Antrim. In the 1850s, a surveyor searching for precious metals discovered a thick layer of rock salt under about 600ft of rock. The salt was initially removed by pumping water down shafts and pumping the resulting brine mixture back up, before evaporating the water to leave salt crystals behind. This is not something Medieval, Iron age and Bronze age Irish could have done. So the sea was the only source of salt for the ancient Irish. But how did they extract the salt from the sea water?

We know that there are two ways for extracting salt from sea water: by solar evaporation and by evaporation through boiling. Now in order to extract the salt from sea water through solar evaporation you need to have “the correct climate, one for which the ratio of evaporation to rainfall is suitably high”. Basically you need to have dry sunny hot climate, or at least dry sunny hot summers. Now I have been living in Ireland for over 20 years now, and I can tell you that Ireland does not have “the correct climate”… This is what Irish summer is like:

What Irish people mean when they say summer

What Irish summer looks like on satellite images

What an Irish summer day is very likely to look like at least half of the time (Picture taken in July)

You are not going to be extracting too much salt through solar evaporation in this climate.

And yet there are numerous place names along the Irish coast which have the word salt as their root, indicating that these places were salt production areas. For instance Lough Salt in Co. Donegal (which may have had salt pits or deposits nearby, rather than being a salt-water lake); Salt Island on Strangford Lough; the Saltee Islands off the coast of Wexford; Salters Grange in Armagh; Salthill in Co. Galway; and Saltpans townland in Co. Donegal, among many others. Based on this there is a widespread belief that the medieval Ireland was a big producer and exporter of salt. In “A smaller social history of ancient Ireland” we read that in 1300, salt was one of the commodities sent from Ireland to Scotland to supply the army of Edward I. This seems to confirm that Ireland was indeed large producer and exporter of salt.

But in “The Archaeology of Medieval Ireland” by Terry B. Barry we can read that at the same time when salt was sent from Ireland to Edward I, salt together with iron was imported into Ireland from France through ports such as Drogheda…So was the salt sent to Edward a tribute in rare commodity rather than export?

Similarly in the “Ireland before the Normans” by Donnchadh Ó Corráin we can read that the medieval Irish laws have mentions of vessels loaded with cargoes of iron, salt, hides, nuts, honey and wine, and they lay down certain provisions for the landing of cargo ships and the liabilities which they may incur. There are, in addition, numerous references in the literature to the import of wine, salt and iron and to the export of hides and wool.

In “The Economy of Early Medieval Ireland” we can read that  although salt is mentioned in the early eighth-century Críth Gablach, there is no evidence for native salt production prior to the late twelfth century, and all Irish place-names associated with salt production are ultimately English in derivation.  An example of one of the earliest references to “salt pans” in Ireland is found in the Calendar of Documents Relating to Ireland for June 1258, where a land dispute is mentioned between John de Verdon and the Abbot of Mellifont over “three carucates of land in Mulygadaveran and Thulachalyni, and five carucates xcepting three acres used in salt works“.

Now this is very strange indeed. You saw the pictures of what the Irish summer looks like. How the hell is it then possible that the medieval Irish were able to use solar salt pans for the extraction of salt from sea water? Well the answer is something called “The Medieval Warm Period (MWP), Medieval Climate Optimum, or Medieval Climatic Anomaly“. This was a time of warm climate in the North Atlantic region lasting from about 950 to 1250. It was followed by a cooler period in the North Atlantic and elsewhere termed the Little Ice Age. Temperatures in some regions matched or exceeded recent temperatures in these regions, and it is believed that temperatures in the north of Europe were on average 2 degrees higher than they are today. But were summers in Ireland during that period sunnier, less rainy? Very likeley. And if so that would explain the confusion about Ireland being described as salt exporter and salt importer, and all the English place names with salt as their root. Basically prior to 900 the climate in Ireland was too damp to extract salt from sea water using solar evaporation. So salt was imported into Ireland and this was recorded in all the early Irish records. The start of the change of the Irish climate into warmer and drier climate coincided with the Viking and then Norman invasion of Ireland. During that time we see emergence of salt pans along the coast with place names with salt as their root, and salt production and export. Then before 1300 the Irish climate starts changing for the worst and starts getting colder and wetter. And the salt production industry disappear from Ireland and the salt is imported into Ireland once again which was recorded in the late medieval records. Then the climate starts warming again in the 18th century and hey presto salt works appear again along the Irish coast. 

Now during the Medieval Warm Period the climate in Ireland was probably the same like the climate we find today in England. Summers were probably much warmer and drier. That allowed the salt to be extracted from salt water using the same method of partial solar evaporation and partial evaporation through boiling, which was until recently still used in England, and which I already described above. Sea water was concentrated in open salt pans and maybe, depending on how severe the climate change during the Medieval Warm Period was. If the water could not have been evaporated completely using solar evaporation it was then boiled in metal pots, which have by this time replaced coarse clay pots (biquetage).

But what about salt production in Ireland before this time? Was climate in Ireland ever as good as during the Medieval Warm Period thus making salt extraction possible? Well yes it was. It seems that the climate in the North Atlantic region oscillates quite a bit, and has extreme high temperature peaks roughly every 1500 years with smaller high temperature peeks in between. At least this is what the available data for last 5000 years is showing us.

The Greenland Ice Cores provide a temperature record for the last 5,000 years. Clearly manifest are three temperature peaks which correspond with the archaeologically and historically documented Warm Periods in the North Atlantic region: Minoan Warm Period 1450–1300 BC, a Roman Warm Period 250 BC – 0 AD, the Medieval Warm Period 800–1100 AD. On the chart you can also clearly see the well documented extreme cold period known as the little Ice Age 1350 to 1850 AD.

In “The Bronze Age climate and environment of Britain” by Tony Brown we read that there was an abrupt climate change around 900 BC which resulted in much colder and wetter climate. This climate change ended what is known as “The Bronze Age Optimum (1500—900 (800) year BC)”,  the period of warm and dry weather in north Atlantic region. This period fallowed The Middle Bronze Age Cold Epoch which was a period of unusually cold climate in the North Atlantic region, lasting from about 1800 BC to about 1500 BC.

Now on the above chart you can see that “The Bronze Age Optimum” starts with the sudden sharp rise in temperature during the Minoan Warm Period which started right about 1500 BC. How warm was Atlantic northern Europe during the Minoan Warm Period can be discerned from the fact that during the Minoan warm period, millet was grown in southern Scandinavia. Today Millet is grown in tropical and subtropical regions, it is an important crop in Asia, Africa and in the southern U.S.. The average annual temperature in Mississippi and Alabama where millet is grown today is about 10 degrees, which should be compared with today’s average annual temperature in Denmark, which is 8 degrees.

The temperature after the Minoan Warm Period drops and has another minimum around 1200 BC rising to another maximum around 1000 BC. After that it oscillates around relatively stable low value until it suddenly starts to rise around 250 BC. This is the beginning of the Roman Warm Period

“The Roman warm period started quite suddenly around 250 BC. Some studies in a bog in Penido Vello in Spain have shown that in Roman times it was around 2-2.5 degrees warmer than in the present. The Roman warm period is amply documented by numerous analyses of sediments, tree rings, ice cores and pollen – especially from the northern hemisphere. Studies from China, North America, Venezuela, South Africa, Iceland, Greenland and the Sargasso Sea have all demonstrated the Roman Warm Period. Additionally, it has been documented by ancient authors and historical events.

How warm was Northern Europe during the Roman Warm Period can be seen by the fact that during the culmination of the Roman warm period olive trees grew in the Rhine Valley in Germany. Citrus trees and grapes were cultivated in England as far north as near Hadrian’s Wall near Newcastle.

The temperature then has a sudden drop during the first century AD but it then rises as suddenly and stays stable high until the end of the fourth century AD when it suddenly drops to an extreme low level. It then suddenly rises to extreme high during the Medieval Warm Period….

You can read more about this in “History of Earth’s Climate 7. – Cenozoic IV – Holocene“.

Now what is very interesting is that the oldest red hills (burned mounds consisting of briquetage and ash) salt extraction sites found in England date to right about the beginning of the Minoan Warm period.

In “The English Coast: A History and a Prospect” by Peter Murphy we read that the early evidence for salt production in east England comes from a Red Hill Bronze age site in Fenn Creek, Essex, dated to 1412 – 1130 calibrated BC. The site continued to be used through Iron age and was abandoned during the late Roman period. Translated the last sentence means that the site was used during warm peek periods between the beginning of the Minoan Warm Period and the end of the Roman Warm period when we have such cold and wet climate in England that the solar extraction stopped.

Now there are no red hill type burned mounds in Ireland. But guess what appears in Ireland right about the time of the Minoan Warm Period: our old friends fulachtai fiadh burned mounds. Radiocarbon dating indicates that the majority of fulachtaí fiadh were constructed during the mid to late Bronze Age (1500 – 500 BC), though some Neolithic examples are known. However, some were still in use up to medieval times. This is very very interesting, don’t you think? Were fulachtai fiadh used for salt extraction? Well I believe, like most other researchers today believe, that fulachtai fiadh were multi purpose facilities used for many different things involving liquids and heat. But I definitely believe that some of them were used for salt extraction. 

So how would you use fulacht fiadh for salt extraction? 

Well the simplest way would be to build your fulach fiadh anywhere where the forest grows all the way down to the the seashore. That way you will have easy access to sea water and wood. You would then need to collect lots of round hard rock pebbles from river beds and beaches. You would fill the through with seawater, and heat the stoned in the fire. Then you could proceed in one of two ways.

Do you remember what Strabo reported about methods of brine concentration and salt extraction used by “European tribes” which included  ‘flinging’ or ‘dowsing’ salt brine over hot stones and then collecting and scraping the salt crusts from the stone. “A surprisingly quick process…” Salty water would be kept in the through from where it would be scooped using cups and then poured over a pile of super heated stones, in the same way water is poured over sauna hot stones. Once the stones have cooled down, the salt would be scraped from their surface and the stones would be put back into the fire to be reheated. A new pile of hot stones would be made and the process would be repeated. The stones were certainly fractured due to the heat gradient in such methods as were the cracked stones found at fulach fiadh sites. 

Another possible way in which fulachtai fiadh could have been used for salt production was as a salt pan for evaporating salty water through boiling inside the through heated with super heated stones. You would fill the through with salty water, heat the rocks in the fire and drop them into the through. They would heat the water to the boiling point and eventually after many reheated stones were dropped into the through all the water would be evaporated and you would be left with the layer of salt covering the bottom of the through. 

Believe or not, this exact method of salt extraction through boiling salty water in pits heated by super heated stones was used by Native Americans in the Eastern USA. In the article Historic importance of salt on the website of the Louisiana department of culture, recreation and tourism, we can read that Native Americans in Eastern North America used salt as a condiment and highly regarded it. The DeSoto expedition which explored today’s South Eastern USA in the 15th century observed four ways in which salt was produced. It was gathered in a free state (rock salt),  extracted from the ashes of plants and salt-impregnated sand, but it was most commonly extracted from brine water at salines. The principal artifact identified with the prehistoric salt industry in Eastern North America is the salt pan which was used for extracting salt from the brine. Fragments of these shell-tempered vessels have been found at most salines. This is a complete vessel from Bone Bank site at  Posey County, Indiana.

In the article “Methods for calculating brine evaporation rates during salt production” we can read the detailed description of how these salt pans were used:

“Thick-walled ceramic ‘‘pans,’’ most in association with salines, have been found with capacities ranging from 40 to 400 L. The enormous size and weight of these vessels when filled with brine would have made them practically immovable and suspension over a fire seems equally unlikely. It is suspected that these salt pans were placed in basin-shaped ground depressions (pits) and heated stones from nearby fires were dropped into the pan to facilitate evaporation. The lack of exterior discoloration from fires on many pans and the occasional find of stones inside pans lend support to the conclusion that stone boiling was at least one method utilized by Native Americans to evaporate brine.”

Now this is very interesting. In North America we have clay lined pits heated with hot stones. In Ireland we have stone or wood lined pits heated with hot stones. The capacity of North American pits is 40 – 400 L. This means that the dimensions of the biggest ones are 2 meters long by half a meter wide and half a meter in depth. Guess what. The size of fulacht fiadh throughs varies a great deal from site to site, from rather small pits lined with stones to pools approximately a meter wide by 2 meters long and maybe half a meter or more in depth.

The article “Methods for calculating brine evaporation rates during salt production” then explains how the hot stones were used to evaporate the water from from the salt pans:

“When the hot stones are dropped into the pan, the heat transferred from the stones raises the temperature of the brine up to its boiling point. Any additional heat released by the stone serves to evaporate water and concentrate brine. After about 2 minutes the brine is concentrated to a maximum value of about 29.0 wt% at its boiling point with further evaporation resulting in the formation of salt crystals. The salt crystals forming continues until the stone and brine reach thermal equilibrium. Placing additional hot stones into the pan would continue the evaporation process. Depending on the size of the pan and the amount of hot stones used, the evaporation process can take up to several hours.

From the short timescales involved to obtain salt, it seems this method would clearly be effective in evaporating brine. Unlike suspension of a pan over a fire, stone boiling releases all of its internal heat directly into the brine. However, there may be practical limitations for manipulating large volumes of very hot stones. Stones heated to high temperatures often shatter and large stones would be difficult to transport from a fire to the brine pan. Smaller stones would make handling easier, but would require more repeated firings to achieve the same evaporation as large stones. The smallest salt pan found at the Kimmswick site near St. Louis had a volume of approximately 40 L. Assuming a scenario similar to that outlined above, emplacement of 25 vol% stone into the salt pan would translate to 26 kg of extremely hot stone(s) that would have been manipulated. This seems to suggest that stone boiling may actually require a tremendous amount of human labor to achieve significant quantities of salt…” 

But it seems that Native Americans thought that this effort was worthwhile because salt was such a valued commodity. Considering that the people world over had the same opinion about salt, I would suggest that the ancient Irish would probably also think that the effort involved in extracting salt using fulacht fiadh was worthwhile. 

Interestingly in “The A to Z of Ancient Mesoamerica” by Joel W. Palka we read that in Yucatan and Guatemala the process of evaporating and refining salt was also carried out by pouring salt water into wooden throughs which were slowly drained, leaving the salt behind. An Irish fulacht fiadh trough dug into as well drained, particularly sandy soil and lined with wooden planks, would be even more efficient salt extraction vessel than the clay lined North American salt pit. This is because water would be removed from the through both through evaporation and draining. 

On average sea water contains about 3% salt. This means that if you evaporate 100 liters of seawater you would be left with 3 kilos of salt. Several hours of hard work for 3 kilos of “white gold”? Definitely worth it. Now there is a way to make this process even more worthwhile.  

To do that you would need to built your fulach fiadh next to a salt marsh or a salty shallow lagoon which would fill only during the very high tides. The sea water caught inside the marsh or a lagoon would slowly evaporate over time and get more and more concentrated and salty. You would then boil this partially concentrated salty water in your fulacht fiadh. 

If the weather was particularly sunny and windy the water in these lagoons could get so concentrated (29%) that salt crystals would start forming in the water on their own. But even if the concentration of salt was increased to 6 percent that would mean that the salt yield for the same amount of work would double. 

This is exactly the process that was used in Bronze Age salt extraction facilities in England now known as red hills burned mounds. 

But there is a way to increase the salt concentration in salty water processed in fulacht fiadh even more. By using seaweed. I already mentioned that in Japan people used seaweed to increase the salinity of water which was boiled for salt. They collected and dried seaweed in the sun and wind until salt crystals formed. They then washed the crystals off into vats of sea water, creating a concentrated brine that could be boiled down to yield salt. Irish coastal waters are extremely rich seaweed growing grounds and you can see that this method of increasing the salinity of seawater could easily have been used in fulach fiadh throughs.  I also mentioned another method of increasing the concentration of salt in seawater using seaweed. In England and Netherlands they used ashes of dried seaweed which was burned to heat the salt pans. The ashes which contained a high concentration of salt were mixed into seawater thus greatly increasing its salinity. Now in Irish fulachai fiadh it was the stones which were heated, but it is entirely possible to heat the stones using dry seaweed or a combination of wood and dry seaweed. The resulting ashes could then be mixed into the seawater to increase its salinity. 

That seaweed was used in Ireland in salt production process was first suggested based on linguistic evidence. In “Celtic culture: a historical encyclopedia. Vol. 1;Volume 2” we can read that in Old Irish one of the terms used for salt was “murluaith” =  “muir + luaith” which means “sea ash”. Now the meaning “sea ash” was taken as proof that originally it was seaweed ash which was used as salt. That is possible as we have seen that Native Americans used salt grass ash as salt. But if seaweed ash was used in the process of salt production in ancient Ireland it was most likely used just like it was used in England, for concentrating seawater into brine before boiling. Interestingly the word “luaith” from “murluaith” has another meaning in Old Irish. It means simply “dust”. The picture below shows a rock pool which was filled with seawater during a very high tide or storm and in which subsequently all the water had evaporated, leaving behind white “sea dust”, salt. Collecting salt from this type of rock pools could be the oldest way ancient Irish obtained salt. Hence the name “muir luaith” = “sea dust” could be the oldest word for salt in Irish, the current word “salann” being later import. 


What do you think? I think that the Bronze Age Irish used and highly valued salt, just like the Bronze Age English. And I can’t see any reason why they couldn’t have used a method of extracting it by boiling a concentrated brine solution in a very similar way the Bronze Age English did it. Or by just dripping the salty water on hot stones, a “very effective method” which Strabo reports was used by the “Europen tribes”. Now I am not saying that all the fulachtai fiadh were used for salt extraction. A fulacht fiadh built on top of the hill in the center of Ireland certainly wasn’t. But those built next to the seashore could have been used as very cost effective salt extraction facilities…

The salt extracted in these fulachai fiadh was then used as condiment, for meat and fish curing and for another very important process: wool dying and hide tanning… And guess what, fulacht fiadh could also have been used in these two processes. But I will talk about this in one of my next posts. 

Fulacht fiadh – primitive ale brewery?

In August 2007 two Galway based archaeologists, Billy Quinn and Declan Moore, suggested that fulachta fiadh were used primarily for the brewing of beer. To understand how they came to this conclusion we have to look at what we know about the history of brewing alcohol.

The earliest evidence for brewing of alcoholic beverages was found among the remains of the Neolithic village of Jiahu in Northern China. It seems that as early as 9,000 years ago people of Jiahu made alcohol from fermented rice and honey. The earliest evidence for brewing beer comes from Godin Tepe in the Zagros Mountains in modern day Iran. Here, calcium Oxalate, the principal component of an insoluble deposit related to the production of beer and known as beerstone was found on the inner surfaces of fermentation vessels dated to late fourth Millennium BC. A stamp seal from Tepe Gawra, a site near Mosul, Iraq dated to 4000 BC, shows two figures drinking beer using traditional straws and container.

At Hierakonpolis near Luxor, Jeremy Geller interpreted a site known as HK24A (3100-2890 BC), as a brewery. The brewery incorporated at least six coarse ceramic vats in two parallel rows set within a mud platform and probably originally covered with an ad hoc superstructure to contain the heat. Each vat, with a height of at least 65cm and a maximum diameter of 85cm, in brewing terms, might be considered a mash-tun, in which the infusion of ingredients (mainly emmer wheat and fruits for sugar and taste) was maintained at a warm temperature. Preliminary analysis of the black shiny residue with cereal grains still embedded found within the vats revealed compounds identified with all phases of biosynthetic fermentation. Based on ethnographic parallels, Geller suggested that the production of beer was a two day process: one day to bring the mash to temperature and cool it down and another day to ferment. There is no explicit information on how the vats were heated, but based on the vat dimensions they were probably heated by the hot coals piled around the base of the vats, in the same way the traditional cooking vats are still heated in Serbia.

Given the outlay for fuel necessary to sustain the needed heat, it is possible that the brew was transferred from the vats to ferment elsewhere, thus freeing the vats for another batch before full cooling of the installation. If this were the case, a great deal of beer could be produced on a daily basis.

If used on a full time basis, this brewery could produce 300 gallons a week allowing 2 days for fermentation in the vat. Output could be as high as 300 gallons a day if the liquid was transferred to other vessels for fermentation. This is output clearly far in excess of domestic needs.

The Epic of Gilgamesh contains references to Siduri; an archetypical brewster and barmaid who gave beer, comfort and counsel to Gilgamesh, greatest of the Sumerian kings. Archeological sites throughout the Near East have yielded thousands of cuneiform tablets containing recipes for and prayers in praise of beer. Among the many types of brew made by these ancient brewsters of Sumeria were: black beer, white beer, red beer, beer of two parts, beer from the nether-world, beering for the offering (sacrifice), mother beer, beer for the supper, beer with horns, wheat beer and beer with a head. As in the later society of ancient Egypt, Sumerian-Mesopotamian beers were made from bread loaves called “bappir.” Barley malt was rendered into a bread cake form, crumbled into water, and with the aid of ambient, airborne yeast, fermentation took place. Most ancient societies used honey as a source of fermentable sugar.

For the ancient Egyptians, beer was so important that the hieroglyphic symbol for food was a pitcher of beer and a cake of bread. Egyptian hieroglyphics tell of dozens of varieties of beer for both this world and the next. Pharaohs were routinely buried with tiny model breweries complete with miniature wooden brewers to ensure a regular supply of beer on the arduous journey to the afterworld.

Egyptian beer, called “Hekt,” was widely exported all over the known world: to Rome, Palestine, and as far away as India. Egyptian women brewed their beer in an area of the kitchen called “the pure,” the lady of the house always supervising. Although royal brewers were sometimes men, most Egyptian beer was made and sold by women who developed scores of beer styles. Brown beer, iron beer, sweet beer–lagered with dates, neter or strong beer, white, black, and red beer and Nubian “boosa”, were just a few of the beer styles commonly made. Special brews for religious purposes included Friend’s beer; the beer of the Protector; Hemns or old beer; the Beer of Truth; the beer of the goddess Maat; and Setcherit, a narcotic beer using as a sleeping draught. Hops were unknown to the ancient Egyptians although bitter herbs like Lupin and Skirret were often used to bitter the brew or served as an appetizer with the beer itself.

In Africa, beer is still made using the same ancient recipe and procedure. Red or white sorghum (or millet) is placed into cold water to swell and germinate.  A few days later, it is piled up in a basket, and after it has germinated a few more days, it is dried in the sun and is then pounded into flour.

A large beer making pot, like this one from Mambila – Nigeria, Cameroon, is half filled with water. 

To see the scale of these pots, here is a picture of one being made.

You can see that they are the same size as the large cooking pots from Serbia or large Beakers from Ireland. 

Coal is piled around the base of the pot and water is heated until boiled. The flour is then poured into the boiling water.  The resulting porridge is continually stirred with a wooden stick, while cold water is progressively added.

When the large pot is filled with cold water, a little sour banana beer or yeast is poured in for fermentation, and the slurry is allowed to settle to the bottom. Beer is then drunk from the fermentation pot using straws.

Or can be drunk from gourds

Pictures of the primitive beer brewery in action in Nigeria can be seen in a brilliant article entitled “Chapalo: Millet Beer, Julia Child… and Hookers” which you can find on the great blog entitiled “Cooking outside of the box”. 

The author of the article describes the brewing of “chapalo”, local brew which is made from red millet, but which can also be made of sorghum, or a combination of both. 

First, the millet is washed in large buckets of distilled water kept in clean, plastic garbage cans. Then the grain is transferred to the cauldrons. These are covered and left to boil for two days, after which the contents are strained through a large, loosely woven basket into a wide, shallow pan. Once the honey-brown liquid is collected, the pan is placed in the shade of a straw mat hangar that also serves as a bar. Yeast is added, and the chapalo is allowed to cool and ferment for one day before it is served to the customers…

Millet beer is still brewed in pots and vats in the same way in other parts of the world. 

Here is a woman from Pathak India brewing millet beer in pots heated with charcoal piled around the bottom of the pots.

In the Balkans this type of millet beer is called “boza“. Boza is a thick, fermented beverage (containing up to 4 percent alcohol) with a sourish or sweetish  taste. The boza is made of various kinds of flour (barley, oats, corn, wheat), but boza of best quality and taste is made of millet flour.

To make boza slightly roast the flour (until rosy in colour). Take care not to get it burnt. Mix it with only a bit of lukewarm water. Pour the mixture into a pot filled with the rest of the water and put it on the plate. Add the sugar and leave the liquid to boil stirring it once in a while. Keep boiling for 5-6 minutes still stirring. Remove the pot from the fire and let it cool. Add 1 teacupful of boza or yeast to start fermentation. Leave the mixture in a warm place for 2-3 days to ferment. That’s it. You can now drink it and enjoy it.

Do you think its funny that the name for grain ale in the Balkans is the same as the Nubian name for beer “boosa”? I do. I will write more about it in one of my next posts…

The world’s earliest written recipe, a Sumerian cuneiform tablet dating to 1800 BC, describes the brewing of beer.

The tablet contains the Hymn to Ninkasi, the goddess of beer who was also known as ‘the Lady of the inebriating fruit’. 

The hymn is also the detailed description of the beer production process, whose starting point is preparing the beer mash in a pit in the ground using ‘sweet aromatics and honey’.

You are the one who handles the dough,
[and] with a big shovel,
Mixing in a pit, the bappir with sweet aromatics,
Ninkasi, You are the one who handles
the dough, [and] with a big shovel,
Mixing in a pit, the bappir with [date]-honey.

And this is what made Billy Quinn and Declan Moore conclude that fulacht fiadh troughs could have been used as wort mixing and heating pits. As they say in their article about ale brewing in fulacht fiadh, “considering that a pit was integral to the brewing process in the Fertile Crescent at least 5500 years ago, and that there is no description of how the temperature was controlled during the wort pit brewing. Now the pits, being dug in the ground, can only be heated from the inside. In my article about pit ovens i described constriction and use of pit ovens for baking, roasting and steam cooking. They were all either heated directly by fire burning inside of the pit, like in tandoor pit ovens, or by fire heated stones placed on top of fire burning inside of the pit. Boiling pits can also only be heated from the inside but because they are filled with water, we can’t heat them by lighting fire inside of them. The only way to heat boiling pits is by using stones stones heated on the fire burning outside of the pit. So if pits were used by the ancient Mesopotamians for heating and mixing wort, they could only have been heated using fire heated stones. 

Or not…

This is a view from above of a millet beer brewery in someone’s home in Segou, Mali. 
You can see that pots (cauldrons) look like they are placed into pits dug into the ground. How are they heated you might ask?. If they have been sank into pits, then they surely can only be heated by hot stones placed directly into the liquid, right? 

On the great travelogue called “Jude’s travels” you can find this picture of a woman brewing “pito” beer in Ghana. Pito? “pi to” = “drink this” in Slavic languages??? “pivo” = “pi ovo” = “drink this” bear in Slavic languages??? 

Leaving this linguistic enigma aside, the important thing to notice on this picture is that what you are seeing is the same type of brewery like the one from Mali, with cauldrons “sunk into pits”. But actually an artificial hill was made from clay around cauldrons mounted on stones fixing the structure in place. Fire is burned in the space between the stones holding the cauldron.

This is a great film, showing how beer is brewed in one of these primitive breweries in Ségou.

So is it possible that what was in the above “recipe” described as a “pit” which could only be heated by inserting hot stones into the liquid contained within it, was actually a pot mounted into a pit in a clay hill brewery like the one on the above pictures, and which was heated by the fire burning below the pot??? I mean everywhere else in the world people used pots and vats heated from the bottom to make beer, right?

Wrong again. 

Guess what. The way of heating wort using fire heated stones was used in Europe until very recently.  In Germany the hot rock method for heating wort in mash tuns was used by Rauchenfels brewery, Bavaria. In Germany the bear made using this technique is called ‘stein beer’ (stone beer). Also, in Finland an unhopped ale called sahti, still served at rural feasts in Finland, is also prepared using the same method of heating wort by immersing hot stones into a wooden mash tun.

You can find more information about “stein beer” and “sahti beer” as well as recipes for making them in on “Brew your own” website. This is a great video showing how making the stein beer is done today in USA. This and this are good articles about sahti brewing using traditional equipment.

So we know that people in Europe used hot stones for heating wort as part of the ale brewing procedure until very recently. But when did Europeans start brewing beer is not clear. It is possible that first grain based meads and ales were brewed in northern Europe as far back as neolithic times. Thousands of charred cereal grains were found at the Neolithic site at Balbridie in Scotland dated to 3900-3500 BC. Pottery from Machrie Moor site at Arran in Scotland dated to the same period, were found to contain cereal pollens. Beaker people who arrived to Britain and Ireland around 2500 BC, probably didn’t drink water out of all those high-status drinking vessels found in their graves. At Bronze Age site at Perthshire, Scotland dated to 1540 BC, archaeologists discovered a ‘black greasy material’ in a food vessel. Pollen analysis indicated that it most likely represented a remain of a fermented grain base alcoholic drink, a cereal-based ale.

So, we have:

1. Mesopotamian ale making recipe which says that the wort was heated and mixed in pits which were most likely heated by fire heated stones dated to 1800 BC (stain beer)
2. British Bronze Age ale dated to 1500 BC
3. A long standing reputation that Irish people have for alcohol consumption without any idea how did the Bronze and Iron Age people in Ireland brew
4. A lot of wood or stone lined pits (troughs) with a fire place and pile of stones which cracked because of the repeated heating and cooling (fulachta fiadh) that no one knows for sure what they were used for.

Knowing all this the question Billy Quinn and Declan Moore asked seems almost inevitable: Were fulacha fiadh ale breweries, where troughs were used as the wort mixing and fermenting pits heated by fire heated stones?
In order to answer their question the two Galway archaeologists decided to try and make beer using their own fulacht fiadh. They dug a pit and placed a wooden trough inside it. They filled it with water and crushed sprouted roasted barley. They then heated stones on a fireplace and used them to heat the mush in the trough to approximately 67° Celsius for about an hour. This produced wort, a glucose-rich syrup solution. To maximise the sugar yield from the grain the wort was sparged (washed trough with hot water) using wicker basket. After an hour the mixture in the trough was brought to a boil for a short time to pasteurise it. The end product was then transferred to storage vessels (copies of beaker culture pots), yeast was added to promote fermentation, flavourings were added to improve taste and several days later the end product was an unhopped ale. Here is the picture showing the two home brewers hard at work and the equipment they used in the brewing process.

You can read the detailed description of their brewing experiment in this article on their website. I would here just want to quote the last two paragraphs:

“We produced what is more properly termed a gruit ale (gruit is a term used to describe the herbal mix used to flavour ale). Through our experiments, we discovered that the process of brewing ale in a fulacht using hot rock technology is a simple process. To produce the ale took only a few hours, followed by a three-day wait to allow for fermentation. Three hundred litres of water was transformed into a very palatable 110 litres of ale with minimal work. The real labour for the Bronze Age brewer would have been gathering, malting and milling the barley. The spent grain provided the ingredients for a dozen malt loaves and the rest was used as cattle fodder. Other than the shattered stone and the remains of the fire, there was no wastage.


So, what is the evidence for brewing? First, the experiment worked. Fermentation caused by windblown yeast even occurred in the leftover mash in the trough within a few hours. Secondly, a number of quernstones have been found in association with fulachts – indicating that grain processing was taking place nearby. Furthermore the fact that hot rock brewing was carried out to an industrial level until the early part of the last century (and indeed is still practised at a vernacular level in Scandinavian Countries today) testifies to the efficiency of the process.

In conclusion beer at its most basic is fermented liquid bread and is a highly nutritious beverage. Our ancestors would have consumed ale on a daily basis as a healthy, uncontaminated, comfort drink. But this does not preclude the fact that in the long Bronze Age evenings and nights, family groups likely sat around a blazing fire telling tales, interacting socially and enjoying the warmth, well-being and genial companionship that ale enhances.

We suggest that the fulacht fiadh was possibly multifunctional, the kitchen sink of the Bronze Age with many conceivable uses. For us, however, a primary use seems clear – these sites were Bronze Age micro-breweries.”

Now this is very interesting. I definitely agree that fulacht fiadh could have been used for brewing. The brewing temperature of 67 degrees Celsius is well below the bubbling boiling temperature and therefore well bellow the high temperature loss through surface threshold. This means that heating the mush in the fulacht fiadh trough is quite efficient. By the way, it is very interesting that the brewing temperature is the same as the hot water acorn leaching temperature. Hot water leaching was also done in pits and I suggested in my last post that fulchta fiadh could have been used as acorn leaching facilities. This raises an interesting question. Was brewing discovered by chance when people applied the same procedure used for acorn leaching on grain?

However, there is a problem with the theory that fulacht fiadh were used for brewing ale. The same problem that the theory that they were used for acorn leaching and food cooking. This is an excerpt from the original article about the fulacht fiadh brewing experiment:

“Seeking authenticity in replicating our Bronze Age ale we decided that our equipment should be as basic as possible. The wooden trough, posthumously donated by Billy’s granduncle, was 60 years old, leaky, wedge-shaped and measured 1.7 m in length, 0.7 m in width with a depth of 0.65 m (roughly consistent with the average trough dimensions from excavated examples). When filled with water to a depth of 0.55 m, it held 350 litres. In an attempt at caulking the more obvious gaps moss and alluvial clay was applied. Where this process was carried out with care no leaks occurred. After digging a pit, the trough was lowered into the ground and water added. Despite some initial leakage we eventually reached an equilibrium in the water level by simply flooding the immediate area.”

Basically fulacht fiadh troughs, which were lined with wooden planks or stone plates were not watertight. This means that they would leak water out into the ground leading to the significant loss of the precious wort. That is if you are lucky, and your fulacht fiadh was built on a dry well drained soil. However, as I have said already in my previous posts about fulachta fiadh, most of them were built on marshy boggy grounds. A leaky trough lining a pit dug in such ground would quickly fill with marshy boggy acidic bad tasting dirty water. Not something you want to eat or drink… So unless the troughs of these bog fulachta fiadh were made in some way completely watertight, which is quite difficult, there is no way they were used for food preparation of any way…What is very interesting is that there is a very easy way to make completely watertight large wooden troughs. All you need to do is to fall a large enough tree, cut a two meter piece of the trunk, and split is vertically into half and then hollow one half to make a trough. A completely watertight trough. The makers of sahti beer use exactly such troughs called kuuran for flavouring and spariging:

And we know that people of bronze age Ireland were perfectly able to make such dugout troughs, because we have found huge dugout canoes made at the same time when fulacht fiadh were made. Like the Lurgan canoe which is over 4000 years old and which was discovered in 1901 in a Co. Galway bog:

These type of troughs were widely used throughout the world. Here is one used for watering cows:

So if one of the main challenges for our bronze age brewers, as our Galway archaeologists turned brewers claim, really was how to heat large volumes of water to make a wort in the absence of suitable large metal containers, a dugout trough one tenth of the size of the above dugout canoe would have sufficed. No leakage problems found in fulacht fiadh plank lined pits…However I don’t think that bronze age brewers had the problem “how to heat large volumes of water to make a wort” at all. If you look at the copies of the beaker pots they used in their brewing experiment, you can see that they are approximately the same size as the largest of the vessels used for brewing beer in primitive societies. They are free standing, and could have easily been heated by hot coals piled around the base, and you could boil hundreds of litres of worth in them no problem…So I don’t think that bronze age Irish would have needed fulacht fiadh troughs to heat up the worth. 

Another reason why I don’t think fulachta fiadh were used as breweries is that if you wanted to make beer, wouldn’t you make it close to the place where you would drink it, like the village where you lived. And close to the granary where you kept your grain. And not in the middle of nowhere, far from any villages, which is where we find fulachta fiadh? This is the way things were done in every early and primitive society that made beer…There were roads in Bronze Age Ireland and I wrote a post about them called “Togher, Tocher – Wooden trackways“. But the road network was tiny and I don’t think most fulachta were on that network. I would have been very impractical to drag the grain from villages to far away fulachta and then drag beer back to the village. 

So I believe that if bronze age Irish did brew beer, they did it in large beakers heated with hot coals piled at the bottom, probably in their villages. But if their eyes were really bigger than their bellies, and they thought that couple of hundred litres of beer was not enough for a party, they could have used , kuuran like dugout vessels, heated using hot stones, again in their villages…

So I really don’t believe that fulachta fiadh were used as breweries, even though they could have been. There are easier and more practical ways to brew beer that were available to the bronze age Irish. Remember, people are lazy and will use the easiest way to do things…As one of my university professors said “Laziness is the mother of all invention”…

But if so, what were fulacht fiadh troughs used for? Well as I explained in my post “Fulacht fiadh – acorn leaching pit?” they could have been used for leaching acorns during acorn food production. But that was not the only thing fulachta fiadh could have been efficiently used for. More in my next posts. Until then drink responsibly 🙂

Fulacht fiadh – acorn leaching pit?

I finished my post in which I presented all the pros (none) and cons (many) on the subject “Fulacht fiadh – a cooking pit?” with this paragraph:

“So I think that we can safely say that fulachta fiadh were not used in the way the mainstream archaeology suggest they were used:  for cooking large amounts of meat in troughs full of water heated by hot stones. The Bronze Age people who built fulachta fiadh had much more efficient ways of cooking large quantities of meat at their disposal.” 

But what about the troughs? Every fulachta fiadh had a trough, so they must have been used for something. But if not for cooking, what were they used for?

In my next few posts I will like to propose what the troughs could have been used for. 

In this post I would like to propose that one of the possible efficient (very important) uses of the Fulacht fiadh’s troughs could have been acorn leaching. 

In my two posts about Irish bullaun stones: “bullaun stones” and “new material about bullaun stones” I presented my theory that Bullaun stones from Ireland and the similar stones with large deep cup marks, were made to be used as mortars for grinding probably originally acorns, and then wild grain, grain, tubers and even ore…

These articles are part of the series of articles about the human use of acorns as food through history, in which I presented the evidence that acorns were a staple human starch food since Paleolithic times. 

You can find these articles here:

Oaks“, “Acorns in archaeology“, “How did oaks repopulate Europe“, “Eating acorns“, “Christmas trees from garden of Eden“, “Acorns in ancient texts“. 

But in order to eat acorns, they first have to be leached. 

So what is acorn leaching?

There were two distinct types of oaks and acorns:

The white oaks whose acorns mature in 6 months and taste sweet or slightly bitter; The inside of the acorn shell is hairless. The bark is light in colour, gray to light gray. The leaves mostly lack a bristle on their lobe tips, which are usually rounded.

The red and black oaks whose acorns mature in 18 months and taste bitter to very bitter. The inside of the acorn’s shell can be hairless but is in most cases woolly. The bark darker in colour. Its leaves typically have sharp lobe tips, with bristles at the lobe tip.

The acorn bitterness is caused by tannin or tanic acid. The concentration of tannin varies from species to species. This is why acorns from some oaks can be eaten raw and some are so bitter that they are inedible unless the tannins are removed. This process of removing tannins from acorns is called leaching. The tannins leached out of the acorns “tan”, color the water.  

These are the same tannins used in tanning leather…

Now there are many different ways in which you can leach acorns.  In my post about eating acorns I wrote about the discovery and development of the acorn processing techniques and tools. 

Most acorn leaching techniques involved soaking acorns in water as water dissolves tannin.

There are basically two main types of water leaching: active and passive. 

Passive techniques involve storing whole shelled or unshelled acorns in baskets which are either submerged in running water or in waterlogged pits. Water slowly leaches tannin and eventually after several days, weeks (running water) or months, years (waterlogged pits) the acorns become edible. This technique requires very little work but takes time and ties the people to the location of the leaching baskets or pits. 
Active leaching involves basically shelling and crushing acorns  and then washing them in cold or hot water. This technique requires a lot of human work but is much quicker. Acorns leached like this become edible after several days to several hours depending on the temperature of the water used for leaching. So you could store your acorns dry into baskets, which is good if you want to carry them around from place to place, and then leach them when you need them. 

It is this second type of water leaching, the active leaching, that I believe the fulacht fiadh’s troughs could have been used for. 

So to do this type of quick leaching you need to first shell the acorns. You can then crush them, because the smaller the pieces, the larger the contact surface area between the acorns and water, and the faster extraction of tannins, but you don’t have to. Sometimes is more practical to leach acorns whole, as it is easier to store whole leached acorns than acorn mush….

Anyway, once the acorns are shelled (and optionally crushed) they can be leached by getting them into contact with water. This is done by submerging the acorns into a container containing fresh water in proportion 1 part acorn 3 parts water or more water. The acorns will sink to the bottom and start leaching straight away turning the water dark. You wait for a while for tannin to dissolve in water and then you pour out or scoop out the tanned water. You then pour in new fresh water and repeat the procedure until the water stops turning dark or until acorns stop tasting biter. Simple. If you can get large enough watertight containers near running water… Like large pots, pits, sand beds, or wood or stone lined troughs. 

The cold water leaching process takes from from 8 hours to several days depending on the tannin content in acorns. You can speed up the leaching process by using hot water. Acorns submerged in hot water leach a lot faster, taking only two to three hours to lose their bitterness. What is interesting is that from the ethnographic data collected among the Native American tribes, we know that they used heated stones for heating water for acorn leaching. The stones used for water heating were carefully chosen so that they don’t fracture during the continuous heating and cooling. The best stones for this purpose are basalt stones as the don’t shatter under thermal pressure. 

There are couple of things that need to know when using water for acorn leaching:

You have to use either only cold water or only hot water for leaching. If you mix cold and hot water or if you put acorns into cold water and then heat the water, the tannin in the acorns will be bound to the acorn meat permanently and you will not be able to remove it. The temperature of water with which you leach the acorns is very important. Heating water over 73 degrees Celsius precooks the starch in the acorn. Cold processing and low temperatures under 65 degrees Celsius  does not cook the starch. Acorn meal that was leached in cold water thickens when cooked, hot-water leached acorn meal does not thicken when cooked.  Also, when you leach the acorns in very hot water you also boil off the oil with the tannins, reducing  acorn meal nutrition. So ideally you would want to leach acorns in water which is hot but not very hot. 

This brings me back to what I said about why I believed that pit meat boiling was extremely unlikely usage for fulacht fiadh. Fulacht fiadh have much larger surface area compared to their dept and “the heat loss due to evaporation of water from a surface of an open tank is totally dominant at higher water temperatures“. What this means is that at boiling temperature, it becomes extremely difficult to keep the water in the shallow trough with the large surface boiling using heated stones for long enough to actually cook meat. But the heat loss trough the surface is much smaller on lower temperatures and these temperatures can be maintained relatively easily using heated stones. Which means that fulacht fiadh could be efficiently used for hot water acorn leaching. 

So how would the hot water acorn leaching be done in fulacht fiadh? First you would fill the trough with clean water. You would then heat the water using heated stones until it is hot but not boiling. You would then pour in whole or crashed acorns. You would occasionally add new heated stones to keep the water temperature high. You would also steer the water with a stick to help the leaching process. You would also from time to time scoop out some of the tanned hot water and replace it with some clean cold, followed by adding heated stones to keep the water hot. 

This leaching procedure is very efficient not just because we are using hot water, but also because we are using stones heated in ashes for heating the water. Every time we drop a heated stone into the trough, hot wood ash which was stuck to the surface of the stone gets washed off the stone and dissolved in water. And believe or not we know that in addition to using hot water to speed up the process of dissolving the tannin, some cultures also used wood ash to induce chemical reactions which transform tannic acid into harmless chemicals. Early ethnobotanist Huron Smith (1923, pg 66) documented the Menominee method of processing various oak acorn species: “The hulls were flailed off after parching, and the acorn was boiled till almost cooked. The water was then thrown away. Then to fresh water, two cups of wood ash were added. The acorns were put into a net and were pulled out of the water after boiling in this. The third time, they were simmered to clear them of lye water. Then they are ground into meal with mortar and pestle, then sifted in a birch-bark sifter.

So it seems that acorn leaching is one of the possible uses for fulchta fiadh. Well at least for those fulacha fiadh which were cut into bedrock or into a clay rich soil next to a clean streams. However, as I already said in my post “Fulacht fiadh – a cooking pit?“, one of the key feature of the most fulacht fiadh sites is elevated soil acidity. Basically most fulacht fiadh were located in marshy boggy areas where a hole dug into the ground would quickly fill with water. Acidic marshy water. A very very bad water for cooking food. And a very very bad water for leaching (extracting acid from) acorns. So even though fulachta fiadh could functionally have been efficiently used for acorn leaching, only the ones not located in marshy pit bogs could in reality have been used for this purpose. 

I will continue exploring the possible uses of fulachta fiadh in my next few posts. 

Fulacht fiadh – a cooking pit?

fulacht fiadh or fulacht fian is a type of archaeological site found in Ireland. In England, Scotland, Wales and the Isle of Man they are known as burnt mounds. They commonly survive as a low horseshoe-shaped mound of charcoal-enriched soil and heat shattered stone with a slight depression at its center showing the position of the pit.

Radiocarbon dating indicates that the majority of fulachta fiadh were constructed during the mid to late Bronze Age (c.1500- c. 500 BC), though some Neolithic examples are known. 
Originally it was thought that fulachta fiadh were still in use up to medieval times. But in the paper entitled “Medieval fulachtai fia in Ireland? An archaeological assessment” by Alan Hawkes, published in the Journal of Irish Archaeology, Hawkes concludes that it is unlikely that the burnt mound tradition continued into the medieval period. Fulachta fiadh are the most common archaeological sites in Ireland, with over 4,500 recorded examples, of which some 2,000 are found in County Cork. Permanent structures are rarely found near to fulachtaí fiadh, but small hut sites are common and it is unknown whether early sites were built by permanent settlements or nomadic hunters.

Fulachtaí fiadh generally consist of three main elements: a mound of stones, a hearth used to heat the stones, and a trough, often lined with wood or stone. Troughs may be cut into subsoil or, more rarely, into bedrock.

The site may contain the remains of structures such as stone enclosures or even small buildings, and sometimes multiple hearths and additional, smaller pits. A number of the fulachtaí fiadh pits are approximately a meter wide by 2 meters long and maybe half a meter or more in depth. However, size can vary a great deal from site to site, from rather small pits lined with stones to pools conceivably large enough for people to bathe in.

The exact usage of these sites and even the exact meaning of the word fulacht is still debated. So lets see if I can help this debate in any way. 

The name

In “Lapidibus in igne calefactis coquebatur: the historical burnt mound ‘tradition’” which was written by John Ó Néill and printed in the Journal of Irish Archaeology Vol. XII/XIII, 79-85 we read that:

Many commentators suggest that the Irish word “fulacht” denotes a pit used for cooking. “Fiadh” in Old Irish meant something like “wild”, often relating to animals such as deer. However, all commentators acknowledge significant difficulties in deriving a genuine etymology for the word “fulacht”. As some historical references clearly use the term “fulacht” to describe a cooking spit…the word probably carries a deliberate reference to the Irish words for blood (fuil) and meat (feoil)….Further corroborating evidence that in the Irish antiquity pits dug in the ground were used for cooking, is found in Geoffrey Keating’s early seventeenth century history of Ireland, Foras Feasa ar Éirinn, which describes a pre-Christian tradition of hunters boiling meat in earthen pits, and a late medieval ecclesiastical biography of the Irish St. Munnu, describing the boiling of porridge on fire heated stones

In the “Early Irish Farming: A Study Based Mainly on the Law-Texts of the 7th and 8th Centuries Ad” by  Fergus Kelly we read that:

The early Irish literature also shows that the word fulacht is not only applied to a water filled pit for boiling meat but also to an outdoor cooking pit where meat was roasted on a spit or over an open fire

The cooking

In legend, fulachta fiadh were the cooking place of the Fianna. As they were lead around the country by Fionn MacCumhal, the band of young warriors would feast on wild boar and deer. It had been suggested that the term ‘fulacht fiadh’ meant ‘cooking place of the Fianna’ and indeed on earlier maps the sites are sometimes called ‘fulachta Fian’. 
Now considering that fulacht fiadh consists of a trough (a pit) and a mound of burned and cracked stones, archaeologists suggested that the cooking was done in the trough, with the water being heated by hot stones which were heated in the hearth and then dropped into the trough….

The Ballyvourney reconstruction of fulacht fiadh included successful attempts at heating the water and cooking meat in this manner. In the experiment it took about half an hour to bring 450 L of water to the boil and four hours to cook a 4.5 kg leg of mutton.

Impressive some would say. And the proof that fulacht fiadh were indeed used as cooking pits.

But one of the people who took part in these cooking experiments had this to say about it:

..having used a fulacht fiadh for a day down in Wexford in the way it’s described in the books in Ireland, I have no doubt that the books are wrong. It took a good few hours of constant work by a team of us to maintain the fire, keep the stones going into the water and maintain that boiling water for long enough to cook a joint of meat…So I don’t think that fulachts were used for cooking. There are a lot of much easier ways to cook a joint of meat…“.

The reason why pit boiling is extremely unlikely usage for fulacht fiadh is that its dimensions are all wrong for a cooking pit. They have much larger surface area compared to their dept. Now meat cooking requires reaching and maintaining a boiling temperature in the trough for the duration of cooking. But “the heat loss due to evaporation of water from a surface of an open tank is totally dominant at higher water temperatures“. What this means is that at boiling temperature, it becomes extremely difficult to keep the water in the shallow trough with the large surface boiling for long enough to actually cook the meat. You have to constantly feed the fire in order to heat the stones. You have to keep adding new heated stones into the trough and take the cooled ones out, while engulfed in a cloud of steam for 4 hours. Because of the wide surface and shallow dept the heat will try to escape straight up through the surface which means that you have to constantly stir the water in order to spread the heat. This is a lot of hard work for cooking some meat, and this is exactly what the above participant in the fulacht fiadh cooking experiment concluded after the “successful” fulacht fiadh cooking experiment. It is possible to use fulacht fiadh to cook, but why would anyone bother doing it when we know that there were other much easier ways of cooking large quantities of meat which were available to the Bronze Age builders of fulachta fiadh?

So what other easier procedures could the Bronze Age Irish use for cooking large quantities of meat? Well depends how they wanted to cook the meat.


What is the most efficient way to boil water? When you heat water, the hot water rises. So if you heat the vessel containing water from the bottom, the bottom layer of water will be the hottest and will rise, while the cooler water layers from the top will sink only to be heated and to rise…This natural heat convection means that you don’t have to stir the water to spread the heat. If your vessel is narrow but deep, this heat convection will create a powerful mixing flow which will result in very quick heating of the whole volume of water. Now remember that I said that the heat loss due to evaporation of water from a surface of an open tank is totally dominant at higher water temperatures. Major heat loss can be avoided only by covering the surface. And at the same time the heat loss through insulated walls can be almost neglected.

So if you want to quickly and efficiently bring to boil and keep boiling a large volume of water, you want to put it in a vessel which is the exact opposite of the fulacht fiadh trough. You want something that is narrow, deep, and covered. Something like a cooking pot.

This is why cooking pots used for high temperature high volume cooking have been shaped in the same way since they were invented in late Mesolithic. They are deep and narrow, which minimizes the evaporation surface relative to the volume. This is a 15,000 year old pot from Jomon culture, an early acorn eating culture from Japan,

This is a 6000 year old cooking set from Europe. You can see that the shape of the pot is still the same.

And this is the same type of high temperature, high volume cooking pot still used for high volume cooking in Serbia today. You can see that the only addition to the original design is the heavy lid. These are extremely efficient cooking utensils which require a small amount of wood to cook large amount of food.

This is a great picture showing the size of  these pots relative to the human body. You can see that you can use them to cook over a hundred kilos of food, in this case sour kraut and smoked pork (Serbian bacon and cabbage).

We know that these types of pots existed in Ireland at the time when fulachta fiadh were made. Here are some burial pots found in Ireland dated to 1900-1300BC. They belong to the “food vessel” type funerary vessels found in Irish early bronze age Wedge Tombs and pit and stone cist burials like this one at Bunnamayne, County Donegal. If people were able to make these kind of pots for burials, they were surely able to make them for cooking too (hence the name “food vessels”). The one on the left looks particularly suitable for cooking and very similar to the above cooking pots from Serbia.

So in order to cook hundreds of kilos of meat and veg, in the pots like these, you need to chop the meed and veg and fat, put all in the pot, add water, herbs, salt (sea water), pile hot charcoals near the bottom edge of the pot, and then sit and wait until it is cooked….No hours of hard work necessary.

So why would anyone who was able to make these types of cooking pots torture themselves by cooking in fulachta fiadh? Well they probably didn’t use fulacht fiadh troughs for cooking. 

The cooking hypothesis is rendered even less convincing by the near absolute lack of animal bone or plant material within the troughs. Moreover, the location of many burnt mounds on marshy upland terrain makes the notion of cooking somewhat unlikely: the prospect of carrying large quantities of food to such inconvenient areas seems unappealing. Proponents of this view have argued that the lack of animal material is likely due to preferential decay associated with elevated soil acidity, which is a key feature of burnt mound sites. Now in these marshy areas a hole dug into the ground would quickly fill with water. Acidic marshy water. A very very bad water for cooking food. No normal person would cook food in water like that. Imagine the taste of meat cooked in such water. Now if the fulacht fiadh trough was cut into a bedrock or into a clay rich soil next to a clean stream, we could pour clean fresh water into it and use it for cooking (if we could be bothered going through the torture of the whole procedure), but then we would have had some traces of meat and plant residue, which again were not found. 

So I believe that we can safely discard fulacht fiadh trough as a cooking pit. But there are other cooking pit types which are still used around the world, specifically for large ceremonial feasts where large amounts of meat need to be cooked at once. And they produce a lot of burned cracked stones.

Pit ovens

In wrote a whole article about pit ovens. In short, an earth oven or cooking pit is one of the simplest and longest used cooking structures. It is  also the oldest oven type used by people. The earliest ones were found in Central Europe, and dated to 29,000 BC. They were situated inside mammoth bone yurts and were used to cook mammoth meat.

So how do you make an earth pit oven?

At its simplest, an earth oven is a pit dug in the the ground. A fire is lit at the bottom of pit and let to burn until only hot coals are left behind. The pit walls and the stones placed in the fire absorb and then radiate the heat back towards the center of the pit. This heat is then used to bake, smoke, or steam food inside of the pit. To make the earth ovens more efficient you can line them with stones as they are much better at absorbing and radiating back heat than the ordinary dirt. The food is placed inside the pit, either directly, covered in clay, wrapped in grass or leaves and then the whole contraption is covered with dirt, sealing the heat inside the pit. The stones slowly release the heat and cook the food. after several hours, when the food is cooked, the food is uncovered and taken out of the pit. The cracked stones are discarded on the burned mound and the intact ones are reused. The type of stones used, granite and sandstone can on average be reheated few times before they crack and have to be discarded. If you want to cook a whole large animal like a deer you need to make a fairly large pit and use a big fire and a lot of stones. So if the same cooking pits were used year after year, and we know from ethnographic data the they were, they would relatively quickly produce big piles of burned cracked stones…

An example of cooking pits used for large-scale cooking producing large “burned-rock middens” can be found in Central Texas. 

Is this what the Irish histories meant when they talked about the “cooking pits”? Again this is much much easier way of cooking large amounts of meat than using stone heated large troughs. Possibly, but only on dry well drained grounds. On marshy waterlogged grounds these pit ovens suffer from the same problem that the cooking pits suffer from: seeping marsh water. The seeping water would quickly extinguish any fire lit up in the pit. But there other surface stone ovens, which can be used for cooking of large quantities of meat, which also produce burned mounds and which are not affected by the soil drainage. I will talk about these ovens in my post about stone ovens.

As for boiling using heated stones, don’t get me wrong. Stone water heating was used for cooking all over the world, and particularly for porridge cooking, just as the biography of the Irish St. Munnu describes it. We know that from the ethnographic data collected in United States where hated stones were used for cooking acorn porridge. I wrote about this in my post about eating acorns.

Stone boiling was used when available cooking vessels were baskets or some other type of watertight but not fire resistant container, such as wooden bowls or containers. 

In California,the hot stone cooking was done in this way by the local Native American people. Hot rocks the size of tennis balls were heated by fire. Then, they were put into baskets or wooden bowls or containers filled with water and acorn meal. The stones were stirred in the baskets gently and slowly with a wooden paddle or looped stirrer. When the mixture began to boil it was cooked, exactly like when you make a cereal porridge. The stones were then removed from the basket with wooden tongs. 

Stone Boiling was also used by plain tribes. A bowl-shaped pit would be dug into the hard earth. It would then be made watertight by pushing a fresh buffalo hide, fleshy side up, into the bottom of the pit. The pit would then be filled with water. Large heavy cobbles would be heated in a nearby fire until they glowed red. They would then be carried on a forked stick to the pit. By continually replacing the rocks as they cooled with hot rocks, the water would get very hot. Food would then be added and cooked. The material stacked up on the right is buffalo dung (commonly called buffalo chips). Since trees tend to be scarce on the Great Plains, dried buffalo dung was the standard fuel used by the Plains Indians. This type of cooking was used for cooking things that could not have been cooked in pit ovens which was preferred way of cooking buffalo meat. For instance this type of cooking was used for extracting bone marrow from broken bones.

There is an old story called “Stone Soup“. The story involves a stranger coming to a village, building a hearth and placing a pot of water over it. He (or she) puts in stones and invites others to taste the stone soup. The stranger invites others to add an ingredient, and pretty soon, Stone Soup is a collaborative meal full of tasty things. Not to mention a stone or two. 

So stone cooking was used, and could have been one of the oldest cooking methods ever used. But look at the dimensions of the basket on the picture above. It is again narrow with the dept the same as the diameter, and relative size much closer to the size of the hot stones being dropped in. This means that the water in the basket will be heated to boil and kept boiling much easier then if the cooking vessel was a gigantic hundreds of liters fulacht fiadh trough. O one other thing. This method of cooking was abandoned for cooking in earthen pots heated from the bottom whenever they were available because cooking with hot stones is much harder and time consuming.

Now remember that the early Irish literature also shows that the word fulacht is not only applied to a water filled pit for boiling meat but also to an outdoor cooking pit where meat was roasted on a spit or over an open fire. Cooking pits can also be used for spit roasting.

Cooking spits

In Serbia and in the rest of the Balkans, no major celebration can be imagined without a roasted pig or lamb on a spit. Where I come from, the roasting process always started with digging of a ditch, an oval shaped pit. The pit was then filled with slow burning hardwood which was burned and turned into a charcoal. Once the pit was full of the smoldering charcoal, the spit was put over the ditch and the roasting would start. Basically the pig was a spit roasted over a pit oven.

Again this is a very easy way to cook a very large amount of meat. Actually the easiest. In Serbia they roast whole cows on spits, so a deer or a wild boar wouldn’t be very difficult to cook at all. No wonder this remained through the ages the most favorite method from cooking large quantities of meat.

So if fulacht fiadh or fulacht Fian really was a place where members of Fianna cooked their food using pits, spits and open fire, then pit ovens are the best match. Not only that you can use them for steaming (boiling) and roasting of large quantities of meat in the pit, but you can also use them to cook the same large quantities of meat on a spit positioned over the pit. And if the cooking is done in the pit, the pit ovens produce large quantities of burned cracked stones and particularly charcoal-enriched soil. 

So I think that we can safely say that fulachta fiadh were not used in the way the mainstream archaeology suggest they were used:  for cooking large amounts of meat in troughs full of water heated by hot stones. The Bronze Age people who built fulachta fiadh had much more efficient ways of cooking large quantities of meat at their disposal. But what about the troughs? Every fulachta fiadh had a trough, so they must have been used for something. But if not for cooking, what were they used for? Particularly the ones built on the marshy boggy acidic terrain. I will talk about this in my next few posts.