(Left to Right)The A-B Corporate Culture Yeast Center protects the 137-year old strain of Budweiser and therefore is heavily protected. Inside the Center: samples for a lager and an ale in test tubes. Kendra Bowen, manager-Corporate Culture Yeast Center, removes samples from their cryogenic tanks.
In September, Anheuser-Busch invited a select group of journalists to go inside its St. Louis brewery’s yeast operation. The visit was the first time outsiders have been allowed to see the brewer’s advanced systems for using, transporting and propagating its yeast.
Though sometimes considered the “un-glorified ingredient of beer,” as A-B put it, yeast provides each beer brand with its distinguishing characteristics and taste. “When you talk to people about brewing and home brewing, it’s a lot about the malt and it’s a lot about the variety of the hops,” said Paul Cobet, A-B’s Brewmaster & Director-Technical Center. “Sometimes what doesn’t get talked about all that often is the strain of yeast that is used, and there are a lot of different strains.”
A-B goes to great lengths to protect all of its yeast, including the 137-year-old strain for Budweiser. The Corporate Culture Yeast Center, a highly-secure, windowless five-story building, has only five employees and just a small number of employees in the entire brewery have access to it. The plant has the distinction of being the single global yeast dispatch center for Budweiser brewing and provides strains for other brands for the company’s operations in the U.S. and Canada. A second yeast center in Leuven, Belgium, also houses yeast strains for other AB InBev brands produced throughout the rest of the world.
“The purpose of the Culture Yeast Center is to safeguard the secret holding place of the Budweiser yeast strains,” said Jane Killebrew-Galeski, Director, Zone Brewery Support-Brewing, Quality and Innovation, A-B. “It supplies Budweiser yeast for any location around the world that is making Budweiser. We have a very active program where we have a great process for growing that yeast and shipping it out in a very safe and healthy manner.”
Inside the Center, nearly two-dozen sterile fermentation tanks populate the various floors where yeast, the purveyor of flavor and aroma in beer, are growing and changing. Altogether some 30 barrels of yeast are shipped out each Monday so that every one of the company’s breweries around the world receives a fresh culture. Each one is color-coded to safeguard the shipments and make sure they are not opened prior to delivery. All A-B breweries use the same carefully maintained, pure culture system from the St. Louis facility. This yeast is a direct descendant of the original Budweiser yeast culture used in the 1800’s by Adolphus Busch, the company’s founder.
The A-B Corporate Culture Yeast Center in St. Louis was built in 1976 (prior to that, the yeast was kept in an older building that had been used since the days of Prohibition). Today, A-B utilizes 19 different yeast strains for its beer in North America. “And we have a repository of hundreds of yeast strains that are preserved cryogenically that we can call on for new product styles or any different challenges that we have,” Killebrew-Galeski said.
Unlike the other A-B ingredients, including barley, malt, rice and hops that are grown in fields by farmers, yeast is monitored by a select group of brewers and the propagation process is overseen by brewmasters. The brewers and operators that work there are closely selected and have decades of experience. “They treat the yeast as their children,” Killebrew-Galeski said.
Added Cobet, “The magic is the way these yeasts behave and the way they make a beer taste. For me as a scientist, it’s really about the yeast.” In fact, he said, anywhere from 50 to 75 percent of a beer’s taste can be attributed to its yeast.