Traces of food in Neolithic cooking pots can reveal what was for dinner

Researchers are analyzing organic residue found in 5,500-year-old pots.

Many vessels unearthed from a Neolithic village in Bavaria have organic residue inside them. Experts in micro-botanical and chemical analysis are teaming up to analyze it and discover what the prehistoric cooks who used them were preparing. We speak with organic residue analyst Dr. Tania F. M. Oudemans about what the researchers know so far, and what they hope to discover.

For updates, follow the project on ResearchGate.

ResearchGate: Where were these pots found?

Tania Oudemans: The ceramic vessels were discovered amongst the remains of the Neolithic lakeside dwelling of Pestenacker in Bavaria, Germany. During excavations in the early 1990's, it became clear that Pestenacker was a special and exceptionally well-preserved late Neolithic settlement. The main part of the settlement consisted of nineteen small wooden houses, built in a regular pattern and surrounded by a wooden fence. This part of the settlement burned down after only four years of use, and only one house was rebuilt. It was used for an additional 15 years. So, even though the preserving circumstances were exceptional and Pestenacker became part of the UNESCO world heritage program in 2011, the exact nature of the settlement still remains a matter of study.

RG: Who used them?

Oudemans: The ceramics from Pestenacker have been studied extensively by Barbara Limmer to answer questions about dating and exchange routes with people south of the Alps and into the Czech Republic. The exact dating of the site at 3496 - 3475 BCE makes it possible to imagine the inhabitants of Pestenacker may have had many similarities with someone like Ötzi, who lived only a few hundred years later and a few hundred miles away on the other side of the Alps. The people from Pestenacker were farmers and had domesticated animals, but also still did quite a bit of hunting and gathering, and like Ötzi, had an enormous amount of knowledge about natural materials and used them to make sophisticated clothing, shoes, containers, and a diversity of tools and weapons.

Tania F. M. Oudemans

RG: How will you determine what was cooked in these pots?

Oudemans: So even though we know a lot about the ceramics from Pestenacker, how the vessels were actually used in prehistoric times was never studied. For this project, different specialists will look at the actual remains of the original vessel content, which can still be seen adhering to the inner surface of many vessels from Pestenacker. Dr. Lucy Kubiak-Martens, an archaeobotanist specializing in the analysis of plant macro-remains, will use scanning electron microscopy to study the anatomical features of very small fragments of plant tissues that might have survived the process of food preparation and cooking. Under the SEM these tiny plant remains can be observed embedded in matrices of the food residu. For the chemical analysis I will be using two different analytical techniques for solid materials. The goal will be to identify the remaining chemical characteristics of the residues. We’ll first determine the state of preservation of the organic compounds as well and the homogeneity of the material using Fourier transform infrared micro-spectroscopy. Then, selected residues will be analyzed in more detail using direct temperature-resolved mass spectrometry. This technique gives insight into a broad range of organic compounds, ranging from fats, sterols, waxes, and resinous compounds, to small peptides and markers for charred proteins, polysaccharides, and sugars. This way we can identify different food remains, glues, paints, or wood tars.

RG: Do you have any preliminary results?

Oudemans: The first results show clear food remains, including the presence of emmer wheat and some well-preserved lipids and proteins. Further identification of foodstuffs will follow. Other residues consist of birchbark tar, which is known to have been produced in temperate Europe ever since the Mesolithic. Dr. Laura Kooistra, a specialist in wood and charcoal analysis, identified the charcoal particles in the birchbark tar in order to obtain further information of the production method of the tar. A more extensive study of birchbark tar on other objects from Pestenacker may provide evidence for a whole range of uses such as hafting of flint tools, medicinal applications, wood preservation, or the production of torches.

RG: Are there other projects where you’ve successfully completed this kind of analysis?

Oudemans: Combining micro-botanical and chemical analysis of organic residues in ceramics has proven to be a successful way of identifying vessel use and cooking practices in prehistoric times before. For instance, such studies have proven that small, finely decorated corded ware vessels from sites in the northern Netherlands were not primarily drinking vessels, but ordinary cooking vessels. It had always been assumed that these vessels were used for drinking, and many an image of early farmers slugging beer from them was created. However, these small vessels turned into cooking vessels for cereals, animal fats, and sometimes green vegetables. An amazing contrast! It was exactly the combination of botany and chemistry that made such detailed identifications of the various foods prepared in vessels possible. Naturally, a whole range of new prehistoric recipes are still out there to be discovered.