Caleb Levar: From PhD to Taproom Tech

Bringing Science to the Art of Brewing

When Caleb Levar decided to become a microbiologist during undergrad, he embraced that decision in all aspects of his life. “What that meant for me was starting a sourdough culture for bread, making cheese, and fermenting sauerkraut,” he says. “Beer was something I did as well, and it turned out that I was alright at it.”

After graduating from the Bond Lab one year ago with his PhD, Levar took his talents to the taproom, joining Fair State Brewing Cooperative as resident microbial expert. “The goal of an academic program is to teach people how to be better problem solvers,” he says. “Everything that we do every day in the brewery is problem solving.”

For instance, many common types of beer are brewed using pure cultures of standard yeast, Saccharomyces cerevisiae, due to its reliable consistency. Yet adding in unique fermenters like Lactobacillus (a common microbe in yogurt and sauerkraut) can dramatically enrich and diversify a brewery’s offerings. That’s why brewers of all sizes are now experimenting with cultures of mixed microbes.

Working with multiple bacterial species or strains, however, introduces the risk of cross-contamination. Additionally, different microbial communities often compete for or work together synergistically to consume available sugars in the slurry. Levar often makes use of his academic training to precisely manage the complex microbial interactions occurring in every batch.

At a large brewery, experimentation with mixed culture fermentations is more difficult due to sheer batch size. At Fair State, however, a batch might fill only a handful of barrels, which makes the problems that arise more manageable and reduces the risk of dumping huge volumes of botched beer.

“Brewing is not a glamorous job,” says Levar, noting that 90% of the work is plumbing and janitorial. Tanks must be frequently scoured and waste disposed of. Because different activities occur on different days, wastewater quality can vary dramatically from day to day at microbreweries. “There’s water everywhere, and a lot of it goes right down the drain,” he says. All of this leads to a heavy load on the municipal wastewater service, creating a need for new ways to clean up.

“One of the fundamental missions of the U of M and the BioTechnology Institute is to interface with the public and with industry and to help find solutions to uniquely Minnesotan problems,” says Levar, who will shortly open the doors to Oakhold Farmhouse Brewery, a brand new venture in Northern Minnesota. Meanwhile, he continues to nurture that exact same sourdough culture he started in undergrad.

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