1 September 2013

We Are What We Ate

Say cheese, but when? 
The processing of milk and particularly the production of cheese were critical in early agricultural societies as it allowed the preservation of milk in a non-perishable and transportable form and, of primary importance, it made milk a more digestible commodity for early prehistoric farmers.


However, while we do know a fair amount about the human diet, both past and present, we don’t actually know very much about how and where cheese making first happened. Recent research published in Nature provides unequivocal evidence that people in northern Europe were making cheese more than 7000 years.

By analysing fatty acids extracted from unglazed pottery pierced with small holes excavated from archaeological sites in Kuyavia (Poland) dating from around 7000 years ago, the researchers showed that dairy products were processed in these ceramic vessels. Using lipid biomarker and stable isotope analysis, researchers examined preserved fatty acids trapped in the fabric of the pottery and showed that the sieves had indeed been used for processing dairy products.  Milk residues were also detected in non-perforated bowls, which may have been used with the sieves.

By way of contrast, the analyses of non-perforated pottery (cooking pots or bottles) demonstrated that they were not used for processing milk.  The presence of ruminant carcass fats in cooking pots showed that they were likely used to cook meat, while the presence of beeswax in bottles suggests the sealing of the pottery to store water. The analyses thus showed that the people who lived here used different types of pottery in very specific ways – sieves (and maybe bowls) for cheese-making, cooking pots for cooking their meat and waterproofed bottles to store and carry water.

Mélanie Salque, a PhD student from the University of Bristol and one of the authors of the paper said: ‘Before this study, it was not clear that cattle were used for their milk in northern Europe around 7000 years ago.  However, the presence of the sieves in the ceramic assemblage of the sites was thought to be a proof that milk and even cheese was produced at these sites.  Of course, these sieves could have been used for straining all sorts of things, such as curds from whey, meat from stock or honeycombs from honey.  We decided to test the cheese-making hypothesis by analysing the lipids trapped into the ceramic fabric of the sieves.

‘The presence of milk residues in sieves (which look like modern cheese-strainers) constitutes the earliest direct evidence for cheese-making.  So far, early evidence for cheese-making were mostly iconographic, that is to say murals showing milk processing, which dates to several millennia later than the cheese strainers.’

Peter Bogucki one of the co-authors of this new study and proponent of the cheese strainer hypothesis nearly 30 years ago notes that: ‘As well as showing that humans were making cheese 7000 years ago, these results provide evidence of the consumption of low-lactose content milk products in prehistory.  Making cheese allowed them to reduce the lactose content of milk, and we know that at that time, most of the humans were not tolerant to lactose.  Making cheese is a particularly efficient way to exploit the nutritional benefits of milk, without becoming ill because of the lactose.’