Beer is the product of fermented grains in the presence of yeast and/or bacteria in a controlled aqueous environment. The earliest evidence of human brewing was found by Dr. Patrick McGovern at the 9000 year old Neolithic dig site, Jiahu, in the Central Chinese province of Henan.
The components of jarred residues were examined by McGovern and other archaeologists to determine that rice, grape and other plants were used to produce a very probably fermented beverage. This beer was recreated Dogfish Head Brewery in a beer called Chateau Jiahu.
Dr. McGovern is also credited with the discovery of the oldest barley beer found in Iranís Zagros Mountains, dating to 3400 BC.