PRINCETON (US) — Milk byproducts left in pieces of pottery suggest ancient Europeans, who were mostly lactose intolerant, knew how to separate cheese curds from whey.
As a young archaeologist, Peter Bogucki based his groundbreaking theory on the development of Western civilization on the most ancient of human technology, pottery. But it took some of the most modern developments in biochemistry—and 30 years—finally to confirm he was right.
The sketch shows a sieve reconstructed from ancient potsherds that may have been used in early cheese-making. At right, a clay fragment found to hold dairy lipids. (Credit: Mélanie Salque/U. Bristol)
In the 1980s, Bogucki theorized that the development of cheese-making in Europe—a critical indicator of an agricultural revolution—occurred thousands of years earlier than scientists generally believed.
It was impossible to prove that bits of perforated pottery were the remains of a cheese maker, rather than some other type of strainer, until biochemist Richard Evershed of University of Bristol developed a technique to analyze lipid remnants trapped in ancient pottery.
“Lo and behold, it was chock full of dairy lipids,” says Bogucki. The discovery of milk lipids, a type of molecule signaling milk processing, was a smoking gun.
In an article published last month in Nature, Bogucki and his fellow researchers explain that the presence of milk byproducts found in the pottery provides compelling evidence that farmers used the perforated pots to separate cheese curds from whey.
It also explains how Neolithic Europeans, who were generally unable to digest lactose, were able to use milk for food—the whey retains most of the lactose in milk, allowing the farmers to eat the low-lactose cheese.
“The discovery provides evidence of the manufacture of long-lasting and transportable dairy products as well as the consumption of low-lactose dairy products at a time when most humans were not tolerant of lactose,” says Mélanie Salque, a researcher at the University of Bristol and the lead author of the article.
In the early 1980s, archaeologists began narrowing their estimates of when key farming developments occurred in ancient Europe. In 1981, a key paper was published describing the theory of a “secondary products revolution,” a leap in civilization in which ancient farmers began using livestock for more than just meat.
Then, it was argued that farm communities had adopted dairying sometime between 4,000 and 3,500 BC, earlier than previously thought. Animal bones from sites in the British Isles showed patterns of which cows were slaughtered—lots of young males and older females—it is consistent with what you would find in a dairying economy,” Bogucki says.
Bogucki had noticed an unusual type of pottery at a number of sites around Poland: fragments of pots that had been perforated with small holes. But he did not think too much about them until a chance visit in Vermont.
“My wife and I were driving back from a wedding in Canada, and we stopped at a friend’s house,” Bogucki says. “She had a lot of artifacts from the 19th century that she had gathered from the area and one of them was a ceramic strainer. It intrigued me because the only other strainers of this type that I was familiar with were the ones from Poland.
“I said, ‘What did they use these for?’ And she said, ‘Cheese-making, of course.'”
Honey, fire, or cheese?
Bogucki noted that the sieve sherds were frequently found at sites dating to the Neolithic period, well before the time previously suggested. But the sherds received little attention from archaeologists, who often focused on more spectacular artifacts. When sieves were mentioned in scientific literature, a variety of uses were proposed ranging from honey strainers to braziers. Bogucki found them unconvincing.
“Why raw honey should require straining in the first place is difficult to answer, for it would seem that it is perfectly usable straight from the comb,” Bogucki wrote. “The case for the Neolithic perforated vessels as braziers or ember-holders is equally difficult to support but maddeningly tough to demolish, although it seems rooted in a somewhat romantic view of prehistoric rural life.”
Using data he collected from dig sites in Poland, Bogucki analyzed animal remains from Linear Pottery Culture settlements and concluded that Linear Pottery settlers seldom hunted for food and relied heavily on cattle. There were also almost no remains of pigs, a far more efficient meat source than cattle.
Bogucki also determined that raising cattle for meat alone would have made no economic sense for the Linear Pottery farmers who carved grain fields from dense forests. He estimated that the herds would have consumed too much food over too long a time to justify raising them simply for slaughter. Cheese, on the other hand, allowed for a storable and continuing food source.
“Linear Pottery communities clearly had access to milk; to ignore such a resource would negate any economic advantages gained from keeping domestic cattle in the central European forests,” he wrote.
But production of milk alone would not justify dairy farming, as Bogucki explained recently. “It only makes sense if you can convert it into something that is storable and will get you through the winter and into the next season,” he says.
Source: Princeton University