On 23 April 1516, in the Bavarian town of Ingolstadt, Dukes Wilhelm IV and Ludwig X issued an ordinance on how beer should be made and sold. Centuries later it would be celebrated as the Reinheitsgebot, the “purity law,” and held up as proof of German brewing virtue. The real history is a little messier, and more interesting.
What the law actually said
The key passage says that beer in Bavaria should be brewed from only barley, hops and water. Much of the rest of the ordinance deals with prices. It sets how much beer could cost in summer and winter and punishes innkeepers who charged more or served short measures. Brewers who broke the ingredient rule could have their beer confiscated.
Yeast is famously missing. Brewers knew that the foam or sediment from one batch could start the next, but the microbe itself would not be understood until the nineteenth century. Later versions of the rules added yeast, and “barley” was broadened to “malt.”
Why Bavaria wanted it
Historians generally point to several motives. One was food security. Limiting brewing to barley kept wheat and rye available for bakers, which mattered in years of poor harvests. Another was protecting drinkers from additives. Some brewers used herbs and other substances, some of them potentially harmful, such as henbane, to flavour or strengthen beer. A third was price control and tax revenue, as the ordinance’s many price clauses make clear.
The 1516 decree was not the first of its kind. Nuremberg, Munich and other places had earlier regulations. Munich’s 1487 ordinance under Duke Albrecht IV already required barley, hops and water. The 1516 law extended a similar rule across the unified duchy of Bavaria.
The rule against wheat did not last untouched. Wheat beer, or Weissbier, stayed popular, and the Bavarian dukes eventually took control of the right to brew it, turning it into a lucrative royal monopoly in the seventeenth century. The “purity” principle, in other words, could bend when there was money involved.
From ducal decree to national symbol
The word Reinheitsgebot itself dates only to the early twentieth century. The rule spread beyond Bavaria when Bavaria made its adoption a condition of joining the Weimar Republic after the First World War, so from 1919 the principle applied throughout Germany, though national tax law had already required malt-only lagers since 1906, and top-fermented beers kept some exceptions. In 1987 the European Court of Justice ruled that Germany could not use the law to block imports of beers brewed with other ingredients. Today German brewing rules sit in the Provisional Beer Law of 1993, but brewers still proudly print “brewed according to the Reinheitsgebot” on their labels.
Why it matters
The Reinheitsgebot is often called the oldest food-safety law still in force. That is not strictly accurate, but its influence is real. It helped shape the clean, malt-and-hop focus of German brewing and gave the country a powerful marketing story. It also sparks debate. Critics argue that it discouraged experimentation with fruit, spices and other grains, which Belgian and craft brewers have embraced. Whether you see it as a guarantee of quality or a creative straitjacket, few pieces of five-hundred-year-old legislation get raised in toasts so often.