Scientists discover 3,500-year-old cheese buried with mummies in China

Chinese scientists have retrieved ancient DNA of Bronze Age kefir cheese from 3,500 years ago which were obtained from the Xiaohe cemetery, buried alongside mummies in the Tarim Basin in far west China.

The discovery of cheese comes almost two decades after archaeologists uncovered mysterious white substances on the heads and necks of the Tarim mummies, unearthed in the Xiaohe cemetery in China's Tarim Basin, dating back to the Bronze Age.

According to scientists, the dairy remains were identified as kefir cheese, “due to the presence and abundance of proteins from ruminant milk, lactic acid bacteria, and yeast in the samples”.

A study revealed that the Bronze Age Tarim Basin mummies were a local indigenous population with deep Asian roots and taste for far-flung cuisine.

The discovery of kefir cheese has led to important insight with regards to the Xiaohe population, particularly their lifestyle linked to the usage of fermented dairy.

“It appears that the Xiaohe population actively adopted animal husbandry from steppe culture and that the related fermented milk product, kefir cheese, became an important part of the Xiaohe culture and subsequently spread further in inland East Asia,” the scientists said in the study.

The research, conducted by scientists from Chinese Academy of Sciences, the University of the Chinese Academy of Sciences, Peking University Third Hospital, the Xinjiang Cultural Relics and Archaeology Institute, and Xinjiang University was published in the peer-reviewed journal Cell on Wednesday.

Through their findings, researchers have been able to deduce the origins of Xiaohe populations. Early Xiaohe individuals show minimal genetic mixing with other groups, while new mitochondrial data suggests maternal links to both East and West Eurasians.

A kefir breakthrough

Kefir is a traditional drink made by fermenting milk with kefir grains, which contain helpful bacteria and yeast. Kefir cheese is made by draining the liquid from kefir milk.

The Chinese researchers discovered that the kefir cheese was made from cow and goat milk, aligning with historical records of kefir production using ruminant milk.

They noted that the cheese-making process greatly reduced the lactose content, allowing the Xiaohe people, who were genetically lactose intolerant, to consume dairy.

Kefir cheese discovered on the Tarim mummies.Handout / Yang Yimin

Lead author Fu Qiaomei explains that the findings support the idea that "kefir culture" has been present in the Xinjiang region since the Bronze Age. This challenges the long-held belief that kefir originated only in the North Caucasus, now part of Russia.

“Although it was previously suggested that kefir was spread from the Northern Caucasus to Europe and other regions, we found an additional spreading route of kefir from Xinjiang to inland East Asia,” researchers wrote.

Two decades ago, archaeologists had found a mysterious white substance on the heads and necks of several Xiaohe mummies. Suspecting it might be a type of fermented dairy, they couldn't confirm what it was at the time.

According to the Chinese Academy of Sciences, advanced DNA analysis allowed scientists to conduct the world’s first metagenomic study of ancient dairy.