Wang and her team analyzed this ancient alcohol by scraping yellowish residue out of the pottery remains — fragments of vessels they think were shaped for the various stages of beer making. They were found in an underground site in Shaanxi province. Their results indicate a brew made from a variety of wild and cultivated grains, plus a few tubers, such as yam and lily, that would have made the sour suds a bit sweeter. Unfortunately, we won't get to try this historic beverage for ourselves, because the researchers don't know the exact ratio of ingredients used in the recipe.
At the dig site, they report, they found the sort of grain husks one would expect to see scattered around an ancient brewery. Microscopic analysis of the residual gunk inside the vessels revealed starch grains that had been mangled as they would be during malting and mashing. They also found what they believe to be ancient stoves used to heat mashed grains — important in the process of transforming the carbs into boozy sugar. The would-be brewery's underground location would also have been ideal, as it would have allowed beer makers to keep their product cool.
With that evidence, Wang and her team think they've found the oldest known beer brewery in China. Archaeologists have found evidence of rice fermentation dating to about 9,000 years ago (which may actually be the first evidence of humankind's tendency to tipple), but barley beer, which showed up in the Middle East about 5,400 years ago, was thought to be a more recent addition to Chinese culture.
In fact, the researchers say, the presence of barley at their archaeological site pushes the grain's Chinese history back by about 1,000 years. Their discovery suggests that barley, which contains high levels of a protein that converts carbohydrates into sugar during the fermentation process, was actually brought into China for the purposes of beer brewing, then slowly made a transition into use as a food crop about 3,000 years ago.
"It is possible that when barley was introduced from western Eurasia into the Central Plain of China, it came with the knowledge that the grain was a good ingredient for beer brewing," Wang told Live Science. "So it was not only the introduction of a new crop, but also the knowledge associated with the crop."
The exotic foreign drink may have helped to foster social interactions and reinforce hierarchies, the researchers wrote in the study. And their dig site indicates that Chinese brewers had already mastered many of the beer making techniques used today.