What is believed to be the world’s oldest cheese has been discovered in a grave in Xinjiang, China.

The cheese was found laid across a mummy’s neck in a 3,600-year-old coffin.

Although the coffin was first opened in 2003, excavators at the time thought the item draped around the woman’s neck was a piece of jewellery.

But scientists have now confirmed the item is no ordinary necklace – it is a piece of ancient kefir cheese.

Kefir cheese, which is still widely eaten today, is made by fermenting milk using kefir grains.

Researchers identified microbes and milk traces in the cheese. Photo: Yang Yimin / University of Chinese Academy of Sciences

The cheese sample is dry, dense and dusty. It is likely to have been well preserved due to the region's dry climate. 

Scientists had previously discovered evidence of kefir cheese making close to the grave but had been unable to find any remains of ancient cheeses until now.

A team led by Chinese paleogeneticist Qiaomei Fu, who is director of an ancient DNA laboratory in Beijin, identified goat and cattle DNA in samples of the cheese.

The samples contained various bacterial and fungal species commonly found in modern-day kefir grains.  

They say the findings show how Bronze Age people consumed dairy and how microbial foods spread through Asia.  They also challenge the widely-held belief that kefir originated solely from the Caucasus Mountains region.

The findings have now been published in the journal Cell.

“This is an unprecedented study, allowing us to observe how a bacterium evolved over the past 3,000 years,” Fu said in a statement. “Moreover, by examining dairy products, we’ve gained a clearer picture of ancient human life and their interactions with the world. This is just the beginning.”