A beer recipe roughly 5,000 years old has been uncovered in China — and researchers call the finding "surprising" because it means people there were importing a critical ingredient from thousands of miles away.
A team of archaeologists from Stanford University, Brigham Young University and two Chinese institutions discovered a cache of ancient brewing equipment — including jugs, pots and funnels — containing remnants of mashed grains and other starches.
The researchers, who were working at the Mijiaya dig site, say their analysis reveals "a surprising beer recipe" containing a grain called broomcorn millet (Panicum miliaceum), barley (Hordeum vulgare), another grain called Job's tears or Chinese pearl barley (Coix lacrymajobi), and some sort of tuber.
The "recipe" they compiled came from the analysis of those grain residues on the interiors of the vessels. Scholars say the evidence points to a culture that understood advanced brewing techniques that are very similar to modern methods.
"All indications are that ancient peoples, including those at Mijiaya, applied the same principles and techniques as brewers do today," said Patrick McGovern, an archaeologist at the University of Pennsylvania, who was not involved with the research.
The earliest references to beer in Chinese literature do not pop up until the Shang dynasty, which spanned roughly 1250-1046 B.C., the Mijiaya site researchers wrote in their study. Some scholars had believed that this Shang-era beermaking culture may have originated in the Yangshao culture — a Neolithic people who lived near the banks of China's Yellow River. The age of the brewing equipment coincides with the time when the Yangshao were beginning large-scale agriculture in the region.
"To our knowledge, our data provide the earliest direct evidence of in situ beer production in China, showing that an advanced beer brewing technique was established around 5,000 (years) ago," the researchers wrote in a study published Monday in the the Proceedings of the National Academy of Sciences.
One of the most surprising aspects of the find lies in one the ingredients involved: barley. Barley was not grown for food in China at the time — it was first cultivated in western Eurasia, and it would not become an important crop in China until the Han Dynasty era, 3,000 years later.
The researchers think barley was brought into the area specifically for beer-making. The farmers in the region probably either traded their own crops for the grain, or grew small patches of it in their fields.
McGovern told CNBC in an email that the beer would have been similar to a $70,000 bottle of Bordeaux that a modern member of the wealthy elite might pull out to "to impress our friends and stay in power."
The beer may have been an "exotic" beverage to the locals, and its possession may have been something of a status symbol. All this suggests that the development of farming in the region led the locals around the Yellow River to develop a complex culture and social hierarchy.
"Like other alcoholic beverages, beer is one of the most widely used and versatile drugs in the world and it has been used for negotiating different kinds of social relationships," the authors wrote.