Around two decades ago, archaeologists found a mysterious white substance on mummies buried in the Xiaohe Cemetery, located in the Tarim Basin of northwestern China. (Image: Wenying Li)

In a remarkable discovery, researchers have uncovered the world’s oldest cheese, dating back 3,600 years, smeared on the heads and necks of ancient mummies in China. This unusual find sheds light on the diets and practices of our ancestors.

Around two decades ago, archaeologists found a mysterious white substance on mummies buried in the Xiaohe Cemetery, located in the Tarim Basin of northwestern China. Recent DNA analysis revealed that this substance is kefir cheese, a probiotic soft cheese produced from cow and goat milk thousands of years ago. The findings were published on September 25 in the journal Cell.

The analysis identified various bacterial and fungal species within the cheese, including Lactobacillus kefiranofaciens and Pichia kudriavzevii. These species are also present in modern-day kefir grains. These grains act as "symbiotic cultures," mixing bacteria and yeast to ferment milk into cheese, much like a sourdough starter.

"This is the oldest cheese sample ever discovered," said Qiaomei Fu, the study’s senior author. Fu is a paleontologist at the Institute of Vertebrate Paleontology and Paleoanthropology in Beijing. She highlighted the significance of this discovery, noting that preserving food items like cheese over millennia is quite rare.

Significance of Kefir Cheese

"Our observation suggests that kefir culture has persisted in Northwestern China's Xinjiang region since the Bronze Age," Fu explained. "This allows us to see how bacteria have evolved over millennia. Additionally, examining dairy products offers insights into ancient human life and their interactions with the environment."

Despite these revelations, the reason for applying cheese to the mummies remains a mystery. This discovery invites further exploration into the practices and beliefs of these ancient individuals, sparking curiosity about their lives.