It takes about 10 liters of water to produce a bottle of beer, while about 65 cu. meters of water is needed to manufacture an automobile.
These figures are estimates worked out by Taikan Oki, a professor at the Institute of Industrial Science at the University of Tokyo, graduate student Tsuyoshi Kondo and other researchers.
In untypical research designed to explain in layman's terms, they calculated the total quantity of water required for the process of brewing beer, starting with when barley is watered and including the water used during the manufacture of machines in a brewery.