A Bronze Age dairy operation
At the archaeological site of Koktepa, about 30 kilometers north of Samarkand, excavations uncovered large ceramic vessels from the Early Bronze Age. Analysis of the residue inside these jars provided direct evidence for a surprisingly early dairy operation. Scientists identified the presence of calcium oxalate, a compound that precipitates during fermentation and is often called "beerstone." By examining the specific shape, or morphology, of the calcium oxalate crystals, researchers can determine the liquid of origin.
The crystal structure found in the Koktepa vessels did not match residues from fermented grains or common livestock milk like that from cows or goats. Instead, the morphology was a clear match for crystals formed during the fermentation of mare's milk. This chemical fingerprint confirms that the inhabitants of this region were keeping horses, but actively milking them and fermenting that milk around 2800 BCE. The discovery represents some of the earliest direct evidence for the production of kumis, a fermented mare's milk beverage still consumed in Central Asia today.
Pastoralists of the Zerafshan Valley
The people who created these fermentation jars were part of a culture transitioning in the Zerafshan Valley. The Koktepa site itself shows occupation from the Early Iron Age (around 1500 BCE) back into the Bronze Age. The evidence of a mare's milk dairy pushes back the timeline for specialized pastoralist activities in the region. Producing kumis requires a significant level of animal husbandry. Mares must be milked multiple times a day, and the milk, which is high in lactose, must be fermented quickly to become digestible.
The fermentation process involves both lactic acid bacteria and yeasts, which convert the lactose into lactic acid, ethanol, and carbon dioxide. This preserves the milk's nutrients but also creates a slightly alcoholic and effervescent beverage with a typical alcohol content between 0.7% and 2.5%. For ancient steppe dwellers, kumis was an important source of nutrition. The presence of these large-scale fermentation vessels at Koktepa suggests an organized and established tradition of producing this essential food source nearly five millennia ago.