The circumstances surrounding the appearance of the first light beer have been revealed: at the court brewery 422 years ago

An accidental mistake led to the creation of a popular drink in Germany

Light beer probably first appeared at the court brewery of Maximilian the Great in Munich in 1602. Scientists have combed through old brewing records to trace the history of brewer’s yeast.

Although Germany is famous for its beer, it is not the birthplace of the popular drink. Recent archaeological research suggests brewing in the Eastern Mediterranean around 13 thousand years ago. Although ale was the typical beer produced from the dawn of brewing until the early 20th century, light beer now accounts for approximately 90 percent of the frothy beverage consumed annually.

Experts in Germany note that the yeast is a combination of two other types, but when and how this happened remained a mystery. The answer now appears to be that lager beer was created by accident when the ale yeast used in Bavaria since the 14th century was inadvertently mixed with wheat brewer’s yeast.

This transition from ale to yeast began when a new species of yeast, Saccharomyces pastorianus, or “brewer’s yeast,” appeared in Germany around the end of the Middle Ages. This is a hybrid species resulting from crossing the top-fermenting brewer’s yeast Saccharomyces cerevisiae and the cold-resistant Saccharomyces eubayanus.

The general assumption was that the hybrid arose when traditional ale fermentation with S. cerevisiae was contaminated with wild yeasts, including S. eubayanus. But researchers believe this is unlikely. Using a detailed analysis of historical records of brewing in Central Europe, they discovered that bottom fermentation of light beer occurred in Bavaria at least two hundred years ago.

They propose an alternative hypothesis that it was S. cerevisiae that contaminated the batch of beer brewed by S. eubayanus, and not vice versa. And through some intriguing detective work, they identified what they believe to be the source of the S. cerevisiae contamination – a wheat brewery in the small Bavarian town of Schwarzach.

Beer has always been a valuable commodity and its production is carefully regulated. In Bavaria, the brewing regulations of 1516 allowed only bottom fermentation and brewing of beer “in the style of lager”. But the neighboring Czech Republic produced excellent wheat beer made from S. cerevisiae and imported it in huge quantities to Bavaria. To limit the economic damage from these imports, in 1548 the Bavarian ruler Wilhelm IV granted Baron Hans VI von Degenberg the special privilege of brewing and selling wheat beer in the regions bordering Bohemia.

Let us explain: Bohemia is a region of the modern Czech Republic, which seems to give the Czechs the right to fame in the creation of light beer. However, in the 17th century, Bohemia was a German land.

When Hans von Degenberg’s grandson failed to produce an heir, the family finally died out, and in 1602 the new Bavarian ruler, Maximilian the Great, himself took advantage of the privilege of a special wheat beer and took over the von Degenberg breweries in Schwarz. In October of the same year, yeast from the wheat brewery was delivered to the Duke’s court brewery in Munich, where researchers believe the famous hybridization occurred and S. pastorianus was born. After this, the researchers show that S. pastorianus strains from Bavaria are distributed throughout Europe and are the source of all modern brewer’s yeast strains.

The researchers’ examination of historical data, together with published phylogenomic data, suggests that the dominance of the brewer’s yeast S. pastorianus developed in three stages. First, the yeast strain S. cerevisiae came to Munich from Bohemia, where brewers had been brewing wheat beer since at least the 14th century. Second, S. cerevisiae, which was introduced to a Munich brewery in 1602, crossed with S. eubayanus, which was already involved in the brewing of Munich-style beer, giving rise to S. pastorianus. Finally, the new S. pastorianus yeast was distributed first in Munich breweries and then throughout Europe and the world. The researchers note that the simultaneous emergence of S. pastorianus with technologically advanced brewing techniques in Munich and the willingness of Munich brewers to share knowledge contributed to the dominance of this strain.

“There is a certain irony in the fact that Hans VIII von Degenberg’s failure to produce a son triggered the events that led to the creation of brewer’s yeast,” commented the article’s author Matthias Hutzler. He added that when one line of the family died out, another began.

“There is no heir – but what a legacy he left to the world!” the expert concluded.