Reinheitsgebot

The Reinheitsgebot, literally "purity order"), sometimes called the "German Beer Purity Law" or the "Bavarian Purity Law" in English, was a regulation concerning the production of beer in Germany. In the original text, the only ingredients that could be used in the production of beer were water, barley and hops. The law has since been repealed but many German and American beers, for marketing purposes, continue to claim to abide by the rule.

The law originated in the city of Ingolstadt in the duchy of Bavaria on 23 April 1516, although first put forward in 1487, concerning standards for the sale and composition of beer.