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Microbes make a MayX delicious

In the MayX “Microbes and Food” students learn a third of foods are made by fermentation.

Last updated May 27, 2024

By Clinton Colmenares, Director of News and Media Strategy

If your first thought when you hear “microbes” is pestilence and disease, Min-Ken Liao has a MayX class for you.

Pathogenic microbes – bacteria, fungi, viruses – are a very small percentage of the microbe world. “They’re actually rare,” said Liao, the William R. Kenan Jr. Professor of Biology, who’s leading “Microbes and Food” this May.

Through fermentation, a lot of beneficial microbes help us make very tasty food and drink. “I’m a microbiologist and I’ve always loved fermented food. One-third of our food is from fermentation – coffee, chocolate, sour dough bread, beer.” She could go on. Wine, cheese, yogurt, kombucha, beans and bean curds, sauerkraut, sausages, olives, pickled cucumbers, pickled beets, pickled carrots, mango pickles, pickled … you get the idea.

A Korean woman stands in front of a table of ingredients wearing a peach -colored apron.

Clara Moon teaches students how to make kimchi.

On a recent Tuesday, in a Plyler biology lab, Andrew La ’27 has his plastic-gloved hands full of microbe-covered yumminess – Napa cabbage, carrots, onions and other vegetables that will eventually become kimchi.

“I wanted to take a bio course that was hands-on and outside of the typical classroom style,” La said. “I thought it’d be really fun to take this class and expand my knowledge in a different way.”

Liao was also aiming to provide something different. “MayX is when we can be creative,” she said, clearly having fun with the kimchi making, cutting vegetables, urging students to get their hands dirty – or, clean.

Clara Moon, an expert kimchi maker who is married to Francis Kim, associate professor of finance, shows La and his classmates how to shake salt between layers of Napa cabbage leaves, which are loaded with microbes, before marinating them with homemade sauces. The salt, Liao says, kills the bad microbes and helps promote the good ones. It also helps leach liquid from the vegetables that the good microbes feed on. “It’s an ecosystem right there!And the salt undoubtedly adds flavors.”

At the beginning of class, Moon gave the students a presentation about kimchi, which developed in her native Korea. Among other facts, the students learn there are more than 1,000 varieties of the fermented vegetables. They vary regionally; some Koreans use flat fish (think flounder) and squid to help the fermentation along. Moon also prepared a feast made from kimchi for students to enjoy.

Fermentation helps preserve foods for winter. But the process also helps break food down so it’s more digestible and nutritious, Liao said.

Throughout the MayX, students learn the names and characteristics of microbes found in foods, how foods contribute to microbial growth and how microbes spoil foods, the methods that control and manipulate microbial metabolisms in food production and preservation, government food safety rules, how foodborne diseases are investigated, the roles of normal gut microbiota and how to make their own fermented foods.

They made trips to the Sierra Nevada Brewing Company and French Broad Chocolates, both in Asheville, North Carolina, to learn more, and consume, fermentation of those fine foods. And they learned how to make sourdough bread, natto, yogurt, ginger ale, black garlic, cheese and more foods.

By the end of the course, Liao hopes students have a different relationship with microbes.

“They can be beneficial, and yummy, too,” she said.

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Clinton Colmenares
Director of News and Media Strategy