A team of archaeologists from the University of California, Berkeley, published a new research paper in the journal Scientific reports , which presents evidence that unglazed ancient pottery sometimes retains microscopic food residues which, upon chemical analysis, can reveal not only what was last cooked in a pot, but also what was cooked over the life of a pot.
The co-principal author, Melanie Miller, a researcher at Berkeley‘s Archaeological Research Facility and a postdoctoral scholar at the University of Otago in New Zealand, explains that the new data allows for a better reconstruction of the specific ingredients that people have consumed in the past, which “shed light on social, political and environmental within ancient communities. ”
The study finds that ceramic cookware records the history of ancient food practices. ( Archaeological Research Center / UC Berkeley)
Chefs and scientists come together to study ancient recipes
Over the course of a year, Miller joined forces with Berkeley archaeologist Christine Hastorf to watch a team of seven chefs prepare fifty meals with different combinations of game, corn and wheat flour. The meals were all cooked in original black clay La Chamba pottery vessels from pre-Columbian South America. According to the newspaper, in addition to cooking with donated road kill deer, they used large quantities of whole grains that they ground and developed into six ancient recipes. Unfortunately, “the doughy meals were bland,” Miller explains, and so the researchers didn’t eat them.
Chemical residues from cooked meals in each pot were analyzed to ascertain whether the samples found on ancient cooking vessels reflected only the last cooked foods within a given pot, or even from previous meals. Hastorf, a Berkeley professor of anthropology and food archeology, says these particular foods were chosen not only because they were available throughout the ancient world, but specifically to help scientists identify their chemical traces inside the vessels. The researchers monitored how the vessels reacted to the isotope and chemical values of the different food combinations.
Pottery samples taken from ancient pottery. ( University of Bristol )
Lipid residues are the key to past meals
In Berkeley‘s Center for Stable Isotope Biogeohemisty the pots were tested in different cooking environments and every eighth test meal was charred to recreate the types of charred residue that are so often sampled by archaeologists inside ancient pots. Adding to the real-life variables found in ancient hunter camps, the pots were cleaned with water and branches from an apple tree. The researchers noted that they were “surprised” that none of these ancient washing tools broke during their experimentation.
An analysis of the fatty lipids that were absorbed in the clay pots was performed at the University of Bristol in England. This showed that “different meal times were represented in different residues”. For example: charred food samples taken from the bottom of pots were loaded with particles from the last meal cooked in the pot, while in the top patina, and in the lipid residue that was absorbed into the pottery itself, the remains of previous meals were also discovered . The paper argues that this new method of observation not only reveals hitherto inaccessible data relating to ancient diets, but also provides information relating to “the food production, supply and distribution chains of bygone ages”.
La Chamba unglazed ceramic pans used in a year-long cooking experiment to analyze chemical residues from meals. Source: Melanie Miller / Nature
Berkley and Bristol: The New Heavyweights of Ancient Food Science
The reason the ceramic samples were sent from California to England is because it was a team of scientists from the University of Bristol who announced a breakthrough in the detection of food on ancient pottery in April. At the time, I described this as “the holy grail of dating techniques” in a Ancient origins news article. According to the document that was published in the journal Nature, the new archaeological dating technique was applied to pottery fragments uncovered from an excavation in East London ‘s Shoreditch which contained traces of meat and dairy products, produced and consumed by the descendants of the first European farmers around 3,600 BC.
This revolutionary new dating technique, known as accelerator mass spectrometry analysis, analyzes fatty acid samples, rather than traditional radiocarbon analysis methods that only examine radiocarbon present in all organic matter. The effectiveness of this system was tested and approved when it correctly dated pottery samples from archaeological sites of known ages. When married to new observation methods coming from California, there is no doubt that the transatlantic collaboration, between the University of Bristol in the UK and the University of California at Berkeley, is leading the charge when it comes to explore the ancient diets of our ancestors and the methods used to prepare and cook them.
Top image: Ancient person eating. Credit: Gorodenkoff / Adobe Stock