A hunk of “whitish mass” discovered in an Egyptian tomb dates back some 3,200 years, potentially making it the most ancient example of solid cheese ever found.

The cheese was discovered in the tomb of Ptahmes, a high-ranking official in the Egyptian city of Memphis during the 13th century BCE. The tomb is located south of Cairo in Saqqara, also known as the “City of the Dead”, and houses ancient artifacts like amulets, clay vessels, and figurines. Measuring more than 70 meters (230 feet) long, archaeologists didn’t think to record its location after its 1885 discovery. It was soon lost under drifting sands, only to be recovered more than a century later.

Researchers resumed excavation work in 2010 and, three years later, were cleaning sand around the outer wall of the tomb when they came across a corner storage area with several broken jars. One contained a “solidified whitish mass” and a piece of canvas fabric they believe could have been to cover the jar or preserve what’s inside it. The team dissolved the white glob, purified its protein constituents, and analyzed them using a process that separates different parts of a liquid called liquid chromatography. They then measured the different molecules present in the sample using a process called mass spectroscopy. They determined it was a dairy product made using cow milk mixed with either goat or sheep milk.

In ancient Egypt, milk had to be consumed shortly after milking or else it would spoil without refrigeration, so it was often turned into cheese and other fermented products like yogurt.

Here’s the catch: traces of an ancient – and potentially deadly – bacteria known to kill livestock and make people incredibly sick were also discovered. Brucella melitensis, the bacteria responsible for brucellosis, is still around today and can spread from animals to people typically after consuming unpasteurized dairy products. The dangerous disease causes animals, such as dogs, pigs, sheep, goats, and camels, to lose their ability to reproduce. If transmitted to humans, symptoms take the form of a generalized illness that includes aches and pains, appetite loss, headache, weakness, and abdominal pain.  

To date, only indirect signs of brucellosis have been discovered on Egyptian bones that date back to 750 BCE. Identifying B. melitensis represents the first biomolecular evidence of the disease from the Pharaonic Period.

Publishing their work in the American Chemical Society’s journal Analytical Chemistry, the researchers say further analysis is needed to confirm the cheese’s age.