Fermentation Is Serious Food Science In Wisconsin

Fermentation — the process by which microorganisms metabolize sugar into alcohol and other byproducts — has been an important part of the human diet for thousands of years. But the art and science of this practice is undergoing a bit of a renaissance, as craft brewing explodes, and as professional and home cooks rediscover its important role in the preparation of many foods.

The connections of fermentation to microbiology, food science and other disciplines is also assuming new prominence at University of Wisconsin System schools and Wisconsin technical colleges, where faculty see opportunities to bring together research, manufacturing and the complexities of flavor. Studying fermentation isn't simply an excuse to whip up some homebrew while earning class credits, though, as UW-Madison Department of Food Science lecturer Hans Zoerb explained in a Dec. 3, 2014, talk for the Wednesday Nite @ the Lab series, recorded for Wisconsin Public Television's University Place.

In Zoerb's classes, students learn about harnessing Saccharomyces cerevisiae (also known as brewer's yeast) and other microbes in processes that yield not just alcohol but do so with consistency and scalability. Zoerb is also hoping his work can build stronger connections between UW and the craft beer world.

Zoerb, who does some small-scale homebrewing himself, offered detailed explanations of brewing and described how Wisconsin academics are working with brewers to explore everything from genetics to quality control. He also discussed what he calls the "Wisconsin Fermentation Initiative," a loose term encapsulating fermentation-science efforts at schools around the state.

Key facts

• Fermentation was probably discovered at least 6,000 years ago. Humans began to "domesticate" yeasts at around the same time they established their grain farming practices.


• Zoerb distinguishes between "fermentation" and "brewing." Fermentation describes a specific metabolic process in which yeast and other organisms consume sugars and excrete alcohol and other substances. Brewing extracts flavor from an organic compound and determines the products' other characteristics (color, sweetness, how heavy or light it is, etc.).


• Brewing embodies many aspects of food science in a multidisciplinary way: It requires the application of biology, chemistry, physics, and engineering.


• Yeast needs nitrogen, sulphur and phosphorous-based compounds to survive. By providing these ingredients, brewers can exert some control over the organisms and shape the end result to their liking.


• Big brewers like MillerCoors use a large-scale scalable brewing process and have donated some equipment to UW-Madison researchers to investigate scalability. These systems are much more difficult to operate than homebrewing setups, but they're designed for efficiency and production of a consistent product.


• UW-Madison geneticists and food scientists are working together to identify other strains of yeast that might perform particularly well in brewing.


• With the rising interest in gluten-free products, UW-Madison food scientists have collaborated with the U.S. Food and Drug Administration to use enzymes that can break down gluten during brewing.


• Zoerb and his colleagues are also working to involve more Wisconsin craft breweries in research and outreach at UW-Madison.

Key quotes

• On the discovery of fermentation: "Nature was very helpful in that any time you leave a bowl of cereal sitting out and it gets wet, something's going to happen. And our ancestors weren't stupid. They probably were able to sit back and put the dots together."


• On why the "fastidiousness" of brewer's yeast is important: "If you have an aggressive organism that doesn't need any help, it'll just go about doing what it wants whenever it wants. And part of control is being able to slow it down, being able to tell when it's going to get where it is."


• On determining the value of different strains of yeast: "The most important part is scalability — does it translate into production?"


• On results in class projects: "We don't drink a lot of this stuff, for obvious reasons. We meet at 7:45 in the morning, which helps control some of that… a lot of what we make sadly gets disposed of or dispatched in other forms. Some of it deserves to be, by the way."


• On things that can go wrong in brewing: "Butterscotch beer isn't the best…. You don't want a goat-y taste either. If you've ever raised goats, you know what I'm talking about."