World’s most popular beer was created by an accident over 400 years ago

MUNICH — Lager, the world’s most popular beer, originated more than 400 years ago in Bavaria due to a brewing accident, according to recent study. Researchers say the yeast used for brewing cold beer, known as Saccharomyces Pastorianus, emerged at the court of Maximilian the Great in Munich. This was the result of an accidental encounter and subsequent mating of two distinct yeast strains. The hybrid yeast is notable for its slower fermentation rate at cooler temperatures, such as those found in caves and cellars.

Historically, Saccharomyces Cerevisiae, a single strain of yeast that ferments quickly and at warmer temperatures, was used to ferment all beers. This yeast strain, utilized for thousands of years, produces what we now call ale.

“Saccharomyces pastorianus, a hybrid resulting from the mating of top-fermenting ale yeast Saccharomyces cerevisiae and cold-tolerant Saccharomyces eubayanus, is responsible for the production of bottom-fermented lager beer. This mating occurred around the start of the 17th century,” says Dr. Mathias Hutzler, the study’s lead author and a beverage microbiologist at the Technical University of Munich, in a media release.

Researchers used a combination of historical documents, evolutionary data, and genetic information to trace the origins of this beverage back to the Munich brewery of the Duke of Bavaria in 1602. There, they discovered that S. cerevisiae contaminated a batch of beer brewed with wild variant S. eubayanus at a wheat brewery in Schwarzach, a small town in southern Germany.

Scroll down to also see the history of brewing in the United States

Pilsner-style lager in large glass with foam
German researchers figure out how lager first developed in Bavaria.
(credit: John Morrissey/ FEMS Yeast Research)

Brewing is among humanity’s oldest industries

There’s evidence of fermented beverages dating back at least 7,000 years in China and up to 13,000 years in Israel. Modern brewing practices were developed in Europe, where, until the Middle Ages, beer brewing was primarily associated with Saccharomyces cerevisiae, the same yeast species still used today to make ale-style beer, wine, and bread.

However, most beer produced today is lager, not ale, which has sparked considerable interest in understanding the historical transition from ale to lager in Europe. Lager brewing utilizes a different yeast species, Saccharomyces pastorianus. The identity of its second parent remained a mystery until 2011 when Saccharomyces eubayanus was discovered in the Patagonian Andes in Argentina.

The study reveals that S. pastorianus evolved in three stages. First, the yeast strain S. cerevisiae, used in Bohemian wheat beer brewing since at least the 14th century, arrived in Munich. This yeast mated with S. eubayanus, which was already involved in beer production, to form S. pastorianus in the Munich brewery in 1602. This new yeast species was initially distributed around Munich breweries, and subsequently throughout Europe and the world.

Lager now makes up approximately 90 percent of the beer consumed annually. Until now, the origins of S. pastorianus remained elusive.

Historically, beer has been a valuable commodity

Its production was carefully regulated. In Bavaria, a brewing law from 1516 permitted only the fermentation of “lager-style” beer. However, in neighboring Bohemia, large quantities of excellent wheat beer made with S. cerevisiae were produced and imported.

To mitigate the economic impact, the Bavarian ruler in 1548, Wilhelm IV, granted Baron Hans VI von Degenberg the privilege to brew and sell wheat beer in the border regions to Bohemia. However, when the Degenberg family line ended in 1602, the new Bavarian ruler, Maximilian the Great, took over the special wheat beer privilege and the von Degenbergs’ Schwarzach breweries.

In October of that same year, the yeast from the wheat brewery was transported to the Duke’s court brewery in Munich, leading to the creation of S. pastorianus.

“There is a certain irony that the inability of Hans VIII von Degenberg to produce a son triggered the events that led to the creation of creation of lager yeast,”  notes Dr. Hutzler. “As one lineage died out, another began. No heir – but what a legacy he left for the world!”

The study is published in the journal FEMS Yeast Research.

A brief history of beer brewing in America:

1612: The first known New World brewery is established in the Dutch colony of New Amsterdam (now Manhattan).

1770s: Home brewing is common practice in colonial America, but commercial brewing is also taking off. Some of the founding fathers, like George Washington and Thomas Jefferson, are known to have brewed their own beer.

Mid-1800s: The influx of German immigrants to the U.S. introduces lager beer, which becomes popular due to its relative ease of production and storage compared to English ales.

1873: There are over 4,000 breweries in the United States, largely due to the wave of German immigration.

1919-1933: The 18th Amendment is passed, ushering in Prohibition. The production, sale, and distribution of alcoholic beverages is outlawed. Some breweries survive by producing “near beers” (beverages with very low alcohol content) or by pivoting to other products like sodas or malt extract.

1933: Prohibition is repealed with the 21st Amendment. The beer industry begins to recover, but many breweries have gone out of business.

Late 1970s: Home brewing is federally legalized, paving the way for the craft beer revolution.

1980s-1990s: The craft beer revolution takes off. Microbreweries and brewpubs proliferate across the country, offering a wide variety of styles and flavors.

2000s-Present: The craft beer industry continues to grow, with a boom in the number of breweries and the variety of beers available. As of 2021, there were over 8,000 breweries in the United States.

South West News Service writer Mark Waghorn contributed to this report.

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