The young woman died about 3,600 years ago – but the dry desert environment in the Tarim Basin in what is now Xinjiang in China has made it possible for not only her remains and clothes to be preserved. When archaeologists examined the grave about twenty years ago, they also found pieces of cheese, almost arranged like a necklace.
Cheese residues were found on the necks and heads of several of the naturally mummified remains in the cemetery. It is described as the oldest known cheese that has been discovered in the world.
"Rare opportunity"
In a new study, published in the journal Cell, Chinese researchers have conducted genetic tests in an attempt to learn more about the production.
Food like cheese is extremely difficult to preserve for thousands of years, which makes this a rare and valuable opportunity, says Qiaomei Fu, paleogeneticist at the Institute of Vertebrate Paleontology and Paleoanthropology in Beijing and the study's lead author, in a comment.
Studying the ancient cheese in detail can help us better understand our ancestors' art and culture.
Different milk
The researchers managed to find traces of DNA from both cow and goat in the three samples analyzed. This suggests that milk from both animals was used in the ancient cheese – but without being mixed.
By sequencing DNA from microbes, the researchers could also confirm that it was kefir – which is still eaten today. It has long been assumed that kefir originated solely in the northern Caucasus region, in present-day Russia. But the researchers' analysis supports another hypothesis, which suggests that it may also have originated from Tibet.
The fact that the cheese was buried with the dead suggests that it may have been a highly valued food item. When it was placed in the grave, the cheese was likely soft and sour, not unlike modern kefir, the researchers believe.