Episode 22 of Through the Gates aired via SoundCloud Sunday, July 24
Water. Hops. Malted barley. Yeast.
Put them together and you have a delicious beer — usually.
But as IU molecular biologist Matthew Bochman shares on this week’s podcast, conditions common to the production of certain craft beers can sometimes inhibit their production, risking a growing segment of a nearly $55 billion industry.
Bochman, an assistant professor in the IU Bloomington College of Arts and Sciences’ Department of Molecular and Cellular Biochemistry and a craft brewing consultant, was lead author on a recent paper analyzing production of sour craft beers. Specifically, the researchers studied “terminal acid shock,” a condition that occurs when the high acidity in sour beers can cause the yeast to go dormant. The research was conducted in collaboration with Upland Brewing Co., a Bloomington, Ind.-based craft brewery.
Bochman happened upon the project during a site visit to Upland’s brewing facility with his IU biotechnology class, when one of the brewers asked for advice on a yeast-killing phenomena happening with two of its dozens of sour beers. Bochman and his co-authors — Caleb Staton and Adam Covey of Upland; Cody Rogers, a graduate student at IU Bloomington; and Devon Veatch, a student at Ivy Tech Community College of Indiana — conducted an analysis that led them to the issue. The particular combination of sugar and yeast in these two, highly acidic beers was causing the yeast to metabolically shut down and hang out, waiting for the environment to change.
“(The yeast) were waiting for somebody to rescue them. And we did,” Bochman said. By adapting the beer to the stressors — giving it an early taste of the stressors that were going to hit them — they found an in-house solution: growing the yeast in a nutritious “rich medium” and then cutting it 50/50 with the beer they wanted to carbonate.
The new bottling technique discovered during this process can be used by home brewers and craft brewers alike. Bochman was also the recipient of $13,000 from the Johnson Center for Innovation and Translational Research at IU Bloomington. The one-year grant funded the establishment of Wild Pitch Yeast LLC, a company that assists craft brewers and homebrewers with the extraction of brewer’s yeasts from local sources such as berries, flowers and tree bark, offering the results for re-sale.
Through the Gates: IU This Week is a collaboration of the Office of the Provost and Executive Vice President, The Media School in the College of Arts and Sciences and the IU Newsroom. All episodes are available through SoundCloud and iTunes, or on the Media School website.