Caleb Levar: From PhD to Taproom Tech

Caleb Levar: From PhD to Taproom Tech

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.

Minnesota Sea Grant

Minnesota Sea Grant

 

http://www.seagrant.umn.edu/

seagr@d.umn.edu

The mission of the Minnesota Sea Grant is to facilitate interaction among the public and scientists to enhance communities, the environment and economies along Lake Superior and Minnesota’s inland waters by identifying information needs, fostering research, and communicating results. With nearly 12,000 lakes and a coast on the world’s largest body of fresh water, Minnesota possesses a bounty of aquatic and coastal resources. Through scientific research and public education programs, Minnesota Sea Grant works to enhance Minnesota’s coastal environment and economy.

Large Lakes Observatory

Large Lakes Observatory

https://scse.d.umn.edu/large-lakes-observatory/research
llo@d.umn.edu

The Large Lakes Observatory expands and communicates knowledge about the past, present and future of large lakes worldwide, where most of the water depended upon by human society is found. The Large Lakes Observatory is an academic and research unit within the Swenson College of Science and Engineering at the University of Minnesota Duluth.  Our focus on the large lakes of Earth means that our work supports the sustainability of well over half of the accessible freshwater on Earth.

Minnesota Lakes in Peril

Minnesota Lakes in Peril

Minnesota Lakes in Peril

UMN researchers use DNA technology to track fecal contamination in Minnesota waters

Imagine your next summer vacation: boating, fishing, or swimming in Minnesota lake country. After months of anticipation, you arrive at the lake to find the beaches closed and the water contaminated by fecal bacteria. Unfortunately, it’s not an isolated occurrence. According to the Minnesota Pollution Control Agency, 40% of Minnesota’s lakes and streams are impaired, with fecal contamination becoming a growing concern. A team led by University of Minnesota microbiologist Michael Sadowsky hopes to provide public health officials with better tools to track the source of contamination and assess the public health risk.

Fecal contamination has been a national issue for decades. In 1977, the US government adopted the Clean Water Act using coliform bacteria (and later the bacterium E. coli) as an indicator for fecal contamination of waterways. Commonly found in the intestinal tract of the warm-blooded animals, E. coli in the water suggested the possible presence of other fecal pathogens, and forced officials to close beaches out of an abundance of caution. As new research indicated that E. coli could survive in nature outside the gut, its value as an indicator of water quality waned. Researchers now focus on the source of bacteria to better assess the public health risks and eliminate contamination at the source.

Initally, Sadowsky’s team relied on DNA and RNA analysis to identify the source of fecal contamination. “We would go into the environment and collect ‘fingerprints’ of individual bacteria,” explains Sadowsky. “These ‘fingerprints’ would then be matched with those of bacteria found within various animals.” Though more accurate that older indicators, DNA fingerprinting only worked about 75% of the time.

Improvements in DNA sequencing technology now allow Sadowsky’s team to analyze fecal samples from a large number of animal species. Using SourceTracker, a software program developed by the UMN’s Knights Lab, the team can compare the distribution of organisms in water samples with those found in the animals.

So far, Sadowsky has successfully identified contamination coming from a few sources. But since contamination often comes from both humans and animal origin, making the source of the contamination harder to identify and remediate.

Though wildlife and agriculture add to the problem, Sadowsky believes that both point and non-point source microbial contamination are symptoms of urbanization. “We have cities with millions and millions of people,” he adds. “Every time you flush a toilet, that water has to go somewhere.”

As the technology continues to improve, Sadowsky hopes the research will help inform public policy. “I want to work with decision makers to establish water quality standards based on the source of contamination.”

Health risks depend on both the source and the level of fecal contamination. With better tools at their disposal, policymakers can continue to protect the public while residents and tourists continue to enjoy summer days on Minnesota’s 10,000 lakes.

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