Duke Wilhelm IV and the Bavarian "Reinheitsgebot" (beer purity law)
All over the world, people believe that the most important contribution made by Duke Wilhelm IV was the adoption of the famous Bavarian beer purity law in 1516, on which Bavarian beer’s good reputation is based (and which, since 1906 applies to Germany as a whole). The law is said to have been the first quality control provision in the food sector worldwide – and of course the most important for beer drinkers. The beer purity law stipulates that beer may be brewed “only from hops, barley malt and water” and nothing more. In other words, that it may not contain any other additives – today still of utmost importance.