Yellowish clumps unearthed in ancient tombs in Northwestern China have been identified as the oldest physical evidence of cheese, researchers report in the Journal of Archaeological Science in February.
The yellowish clumps found around the neck and chest on the mummy of Princess Xiaohe in the Xiaohe cemetery in the Xinjiang Uygur autonomous region are believed to be more than 3,600 years old, making them the oldest cheese remnants known to human beings.
The project is conducted by researchers from the University of Chinese Academy of Sciences and the Max Planck Institute of Molecular Cell Biology and Genetics.
The Xiaohe site is a bronze-age burial site where more than 30 well-preserved mummies have been excavated. It was first discovered in the early 1900s and then rediscovered in 2000. The excavation of the site was credited as one of China's top 10 archaeological discoveries in 2004.
The researchers also observed that the cheese was made with a technique that is still commonly used today in making kefir, a fermented milk drink.
"We have never been able to pin down when kefir beverages or clabber were first drunk. Now we can say that it has existed for at least 3,600 years," says Yimin Yang, researcher of the project and archaeometrist from the University of Chinese Academy of Sciences.
The cheese has long provided people in the desert a sustainable source of protein without having to kill the animals. It also helps them adapt to the long travels of nomadic life, Yang adds.
Milk has played an important role in the development of agriculture and animal husbandry in Europe and Asia. A griddle found in Poland suggests that cheese was made in as early as 6,000 BC. But it was never known how cheese was made at that time because of the lack of fossil evidence.
"We not only identified the product as the earliest known cheese, but we also have direct ... evidence of ancient technology," study author Andrej Shevchenko told USA Today, saying the technique is easy and cheap and works for the common people.
The age of the cheese was identified with the samples discovered in the same tomb, such as seeds and textiles. The cheese was preserved because of the extreme dryness in the desert. The lack of water restrains the growth of microbes, which could biodegrade organic substances, Yang says.
Archaeologists believe it to be either sacrifices or food for the woman in her afterlife. No book has recorded the exact use of cheese in the tomb, Yang says.
"But it does show that milk production at the time was already abundant enough to make byproducts like cheese for people in the desert who were in need of energy," he says.
