Fulacht fiadh - a cooking pit?

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 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.

Boiling

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.