Previously, archaeologists have found barley-based beer dating to 3,400 B.C. in Iran’s Zagros Mountains, grape wine circa 5,400 B.C., and 9,000-year-old Neolithic grog from China’s Yellow River Valley. Now researchers, working together at Stanford, Brigham Young University, and the Shaanxi Institute of Archaeology, have unearthed the world's oldest brewery, along with traces of beer dating back anywhere from 4,900 to 5,400 years old.
The discovery is especially unique, says Jiajing Wang, lead study and Stanford Ph.D candidate, because the beer traces were found at the site of brewing. Typically, such findings are by themselves in storage pits. Wang and her fellow researchers excavated two pits at the Mijiaya archaeological site in northern China, discovering clay pots and stoves that were stained with a yellowish coating and showed visible evidence of being used to grind, steep, and ferment starches.
After testing, the ingredient proved to be broomcorn millet, barley, Job’s tears (a type of grain-bearing plant native to Southeast Asia), and tubers. Based on the findings, the grains were likely ground into a mash before being heated on the stove in the wide-mouthed pots found in the pits. After they had been fermented, a funnel was used to strain out the brew from the leftover grains and transfer the beer into a tall jar with a narrow neck for storage.
To test that they had actually discovered an ancient brewery, the research team brewed a beer based off the ingredients and tools they found. While the process and ingredients acted as expected, the researchers were unable to taste the final product because they had trouble with the grains gelatinizing and trapping the liquid.
The full findings were published in the Proceedings of the National Academy of Sciences. Additionally, researchers say that beer-making may have motivated the initial import of barley from Western Eurasia into the Central Plain of China before the crop became a popular part of agricultural subsistence in the region. That means that before non-native grain became necessary for food in China, it was necessary for beer. “This beer recipe indicates a mix of Chinese and Western traditions — barley from the West; millet, job’s tears, tubers from China,” Wang says.