The World’s Oldest Cheese Was Buried in a Chinese Tomb 3,600 Years Ago. Now, Scientists Have Sequenced Its DNA

About 20 years ago, researchers discovered three ancient mummies in China. They had a strange white substance smeared around their necks, which turned out to be chunks of preserved cheese. Dating back around 3,600 years, it was the oldest cheese ever found.

The mummies were buried in Xiaohe Cemetery, a Bronze Age burial ground in northwest China. Since discovering them in 2003, scientists have been examining the remains and testing the white curds’ proteins. Now, one group of researchers has finally finished extracting and analyzing the cheese’s DNA.

According to a study published this week in the journal Cell, the mysterious curds are kefir cheese—a fermented yogurt-like dairy product. The new analysis is shedding light on cheese-making in ancient Asia.

“This is the oldest known cheese sample ever discovered in the world,” says co-author Qiaomei Fu, a paleogeneticist at the Chinese Academy of Sciences, in a statement from the journal. “Food items like cheese are extremely difficult to preserve over thousands of years, making this a rare and valuable opportunity. Studying the ancient cheese in great detail can help us better understand our ancestors’ diet and culture.”

Researchers identified multiple bacterial and fungal species in the cheese, including Lactobacillus kefiranofaciens and Pichia kudriavzevii—which are found in modern kefir grains. Thousands of years ago, the cheese was likely soft, like modern kefir. But upon their discovery, “these pale-yellow cheese samples smelled of nothing and were powdery to touch and a little crumbly,” as Fu tells New Scientist’s James Woodford.

Finally, by sequencing bacterial genes, the researchers were able to “track how probiotic bacteria evolved over the past 3,600 years” in China, per the statement. The L. kefiranofaciens grains in the mummified cheese are closely related to others from Tibet. The presence of such grains suggests that people in northwest China may have interacted with Tibetans in the Bronze Age, conducting “cross-regional exchanges,” according to the study.

“Our observation strongly suggests the distinct spreading routes of two [kefir microbe] subspecies,” which was enabled by nomadic groups traveling across Eurasia, as Fu tells Popular Science’s Lauren Leffer. These groups likely spread microbes through the trade of dairy products and their storage containers.

“Human-microbial interaction is always fascinating,” says co-author Yichen Liu, also of the Chinese Academy of Sciences, in a statement. “Fermentative microbes played such an important role in the daily life of these ancient humans, and they propagated these microbes for thousands of years without knowing the existence of them for most of the time.”

This study is “unprecedented,” Fu says. It allowed researchers to observe a bacterium’s evolution over 3,000 years, providing a peek into ancient human life.

“It’s a new way of tracking what human cultures were doing long before or in the absence of language or written accounts,” Paul Kindstedt, a cheese historian and food scientist at the University of Vermont who was not involved in the study, tells the New York Times’ Kate Golembiewski.

But despite the cheese’s importance to science, thousands of years of aging have certainly reduced its culinary allure. “I think people don’t want to try it because we see that it’s not that attractive,” Fu tells the Times.

Sonja Anderson | READ MORE

Sonja Anderson is a writer and reporter based in New York City.