This article actually shows that acorns were the first starch food eaten by man, many millenniums before grains...
For those who did not bother clicking on the link here is the intro from the post.
Acorns are usually eaten roasted, and during roasting the thin-walled shells are carbonised and destroyed, which makes the macro particle acorn detection in the archaeological remains very difficult. On dry sites wind would then disperse the acorn ash and make it even more difficult to detect. On wet sites we have another problem and that is that like for most other starch rich seeds, the preservation of acorns in waterlogged conditions is not very good. Acorns only preserve well once charred because the elemental carbon of charcoal is not attacked by chemical or biological processes in sediments. But as I said already, when they are fragmented during or after charring, it can be hard to identify them as the bits get scattered. In Eastern North America where archaeobotanical finds of acorns are abundant, the majority of finds consist of fragments of acorn shell of 2mm or less. This might indicate that in Europe most of the evidence of acorn use may have been overlooked or was not preserved. Because of the absence of macro remains we have to rely on micro remains and they are not easy to detect. To detect micro remains of food plants you need to use flotation technique and microscope analysis. At the submerged Mesolithic site of Tybrind Vig in Denmark which is known for its excellent preservation conditions, acorn use has only been attested by the identification of small fragments of acorn using a scanning electron microscope. The same happened at the sites of Cova Fosca and Roc de Migdia in Spain, which had no previous evidence of acorns, and where the presence of acorn parenchyma was attested only by using a scanning electron microscope. However both these techniques are expensive and require well equipped archaeobotanical laboratories. Because of this there are significant national and regional differences in the intensity of archaeobotanical research, resulting in acorn traces being missed among the archaeological material and in an underestimation of the use of acorns as a source of human nutrition in the past.
This is the main reason why hazelnuts are usually the most frequently found collected plants on archaeological sites. Hazelnut are eaten raw, where the husk is broken and discarded so we have a chance to find big fragments close together. Also hazelnut husks are far more durable than acorn ones. Another reason why acorns are not detected in larger quantities on archaeological sites is because a lot of the acorn processing is usually undertaken completely or partially off site in the actual oak groves, on river edges, collective grinding stone.... which all adds to the difficulty of detecting acorns among the food remains.
Even with all these difficulties in detecting acorns, there is enough archaeological evidence that shows that acorns were much more important food source than most people, including most archaeologists think. The number of acorn finds on archaeological sites is still high. At several Mesolithic sites in Europe, acorns are only outnumbered by hazelnuts, the husks of which are far more durable. Acorns are the most frequently found wild fruits at protohistoric archaeological sites in France. In Spain, acorns are third (after wheat and barley) in terms of frequency of occurrence among archaeobotanical remains, thus even more frequent than legumes such as peas and lentils.
The fact that acorns are no longer considered as being edible is also making it likely that archaeologists would not even look for them when they are looking for human food traces. Also when found on archaeological sites acorns are likely to be misunderstood and misinterpreted as accidental blow in or as animal food. But ethnographic and historical evidence is telling us that in some parts of the world acorns were used as human food until very recently.
During the pre-agricultural period acorns were an important plant food resource for hunter-gatherers in Europe. Archaeological evidence supports the conclusion that acorns have always been an attractive food resource within various resource strategies, including agrarian societies. In prehistoric agricultural communities, acorns may have played a role as food substitute or reserve for bad times, reserved for emergencies, for example when cereal agriculture had failed.
Within the context of agricultural sites acorns are usually located close to fireplaces and in furnaces. Frequently they are accompanied by other crops. In addition, acorns are common finds in vessels and storage pits. They are often shelled and mixed with cereals. Acorns also occur in shallow pits and are also found unshelled. Acorns are found in graves, and their appearance there as sacrificial offering cannot be discounted.
The high number of prehistoric sites across oak growing regions of the Northern Hemisphere where acorns have been found and the large number of acorns recovered from some of these sites are confirming that acorns have been one of the most important food sources for humans in the oak growing regions of the Northern Hemisphere since Paleolithic times.
I will here present the list of all the cultures on whose sites acorns were found among food remains. The list is far from being definitive, and I would appreciate any information about sites that I have missed. But as far as I know this is the most comprehensive list of acorn finds in archaeological material freely available in English on the Internet. And the list reads like "who's who" of the Northern Hemisphere ancient history, containing all the most advanced and important cultures of the Paleolithic, Mesolithic, Neolithic, Copper age, Bronze age and Iron age. I believe that as the archaeobotanical research intensifies, we will see more and more evidence of the use of acorns as food. But I believe that even this much is enough to prove the point. All the references to the original documents containing data about acorns in archaeological sites are listed at the end of the post with clickable links.
I will present the data according to the region. I decided to do that because a lot of the archaeological sites had been occupied over thousands of years and it would be impossible to put them into any one time period. Also presenting the archaeological data according to the region shows that people from certain areas liked eating acorns more than people from other areas and kept eating them over the period of thousands of years spanning multiple cultures. Which opens a question whether acorn eating is linked to a particular tribal of genetic populations.
It is also very interesting that I could not find any data for acorns being found on the sites of the Yamna culture and Cucuteni Trypillian cultre. Why? Did I just miss the available data or were these two cultures different from the rest of the Old European cultures? Is it because these two cultures were the true Steppe cultures as opposed to all the other European cultures which were forest cultures?
I also could not find any data for acorns being found on the sites in Britain and Ireland. Again did I just miss the available data or are Britain and Ireland in some way different from the rest of Europe?
I would greatly appreciate any help in answering these two questions.
