Archaeologists find the world’s oldest cheese spread on mummies in China

The Guinness Book of World Records needs to update its records: the oldest cheese in the world was found smeared on the heads and necks of 3,600-year-old mummies in China’s Tarim Basin. It is several hundred years older than the cheese found in the tomb of an ancient Egyptian mayor.

Cheese-covered mummies are found at Xiaohe Cemetery, part of the Xinjiang Uyghur Autonomous Region. The remains — surprisingly, buried in boat coffins surrounded by miles of sand dunes — date from 2000 BCE to around 200 CE.

Mummy cheese is kefir, which is made by using yeast and probiotic bacteria to separate curds from whey. Scientists discovered mummy cheese decades ago and suspected it was a fermented milk product, but they weren’t entirely sure. Now they’re more certain, as work describing the extraction of ancient cow and goat DNA from the cheese was published today in Cell.

“This is the oldest known cheese “This is the oldest sample ever discovered in the world,” Qiaomei Fu, a paleogeneticist at the Institute of Vertebrate Paleontology and Paleoanthropology of the Chinese Academy of Sciences, said in a press release to Cell.

The team also recovered DNA from microorganisms in the dairy sample—species of bacteria and fungi that survive in modern kefir grains. The team was able to use this information to track how ancient kefir cheeses differed in their bacterial composition from modern ones.

“The results provide new insights into our knowledge of lifestyles, technological-cultural exchanges, and human-microbe interactions in past populations, and open up new avenues for us to explore through microbial genomes how microbiomes interact with human biology and culture to influence human health, behavior, and quality of life,” Fu told Gizmodo in an email.

There are currently two main groups Lactobacillus bacteria from Russia and Tibet, respectively, according to the release. The team found that the DNA in the cemetery cheese was more similar to that of a Tibetan bacterial culture, indicating that kefir cheese did not originate exclusively from the North Caucasus Mountains in Russia.

“Our observations indicate that kefir culture has been cultivated in the Xinjiang region in northwestern China since the Bronze Age,” Fu said.

The shoddy research is the latest look at the Xiaohe mummies, which continue to baffle scientists even after three thousand years. The mummies bear no resemblance to modern inhabitants of the area, leading various groups of researchers to assume that the ancients came from the Black Sea region or the Iranian Plateau. A 2021 paper found that the Xiaohe mummies were direct descendants of ancient northern Eurasians, a human population that was widespread during the Pleistocene and whose genetics survive in the genomes of some modern populations.

Genetic studies of the mummies — and the cheese spreads they carried — reveal a more complex picture of a unique population.