A Brew Safer Than Water
In the 11th century, clean drinking water in Europe was hard to come by, and waterborne diseases were common. Arnold of Oudenburg, a former soldier turned Benedictine abbot in present-day Belgium, took an unusual approach to protecting his community.
He brewed beer. At his abbey in Oudenburg, Arnold encouraged the local population to drink beer instead of water, insisting it was healthier. The brewing process involved boiling, which killed harmful pathogens, making beer a safer choice.
Monastic Brewing and Public Health
The beer consumed during Arnold’s time was “small beer,” low in alcohol and high in nutritional value due to spent yeast. It was often drunk daily, including at breakfast. Arnold and his fellow monks brewed it in large quantities. He also taught the local peasants how to brew it themselves.
During a deadly outbreak of illness, Arnold warned people not to drink untreated water. He urged them to rely solely on beer for hydration, and many who followed his advice reportedly avoided the sickness that spread through the region.
A Miracle in the Mug
One account tells of Arnold having vats of beer distributed to the sick when a plague hit the area. Those who drank it recovered or avoided the illness entirely. This act gained him a reputation as a healer.
Whether seen as divine intervention or simple microbiological fact, the outcome was the same: the beer brewed by Arnold and his monks helped protect an entire community from waterborne disease. His role in this effort earned him veneration after his death.
Honored by Brewers for Centuries
Arnold died in 1087. Reports of miracles at his tomb were investigated and approved in 1121, and his relics were moved in 1131 to the Church of St. Peter in Aldenburg. He became the patron saint of brewers and hop-pickers.
Today, his image often appears holding a mash rake, a tool of the brewing trade. In Brussels, he is honored every July during the “Day of Beer.” But long before any celebrations, Arnold’s practical knowledge of brewing—and its life-saving impact—secured his place in history.
In 11th-century Belgium, disease often spread through drinking water.
Arnold of Oudenburg, a monk and brewer, told people to drink beer instead.
During a deadly outbreak, he distributed monastic brews—and those who followed his advice reportedly avoided illness…🧵👇 pic.twitter.com/xavwlH31xi
— Detective Tiger's Stories (@TigerDetective) June 16, 2025