From Stanford News Service:
Liu, together with doctoral candidate Jiajing Wang and a group of other experts, discovered the 5,000-year-old beer recipe by studying the residue on the inner walls of pottery vessels found in an excavated site in northeast China. The research, which was published in Proceedings of the National Academy of Sciences, provided the earliest evidence of beer production in China so far.
The ancient Chinese made beer mainly with cereal grains, including millet and barley, as well as with Job’s tears, a type of grass in Asia, according to the research. Traces of yam and lily root parts also appeared in the concoction.
Liu said she was particularly surprised to find barley – which is used to make beer today – in the recipe because the earliest evidence to date of barley seeds in China dates to 4,000 years ago. This suggests why barley, which was first domesticated in western Asia, spread to China…
…At the end of Liu’s class, each student tried to imitate the ancient Chinese beer using either wheat, millet or barley seeds.
The students first covered their grain with water and let it sprout, in a process called malting. After the grain sprouted, the students crushed the seeds and put them in water again. The container with the mixture was then placed in the oven and heated to 65 degrees Celsius (149 F) for an hour, in a process called mashing. Afterward, the students sealed the container with plastic and let it stand at room temperature for about a week to ferment.