Savoring wine and cheese and science

Class at Johns Hopkins delves into the science of fermented delicacies

Ben Crane advised his students to take two light sniffs and then one bigger one, as they considered a recent assignment.

“It smells warm,” said one student. “Strawberry!” a classmate exclaimed.

The materials for that day’s class at the Johns Hopkins University were supposed to help train noses to probe for scents of oak, cherry, earth and leather, and even paint thinner or a baby’s diaper.

“It doesn’t smell like a baby diaper,” one student said after taking a whiff of white wine, “but it’s not good.”

The two-week winter class is devoted to the science of wine and anything else that is tasty because it has been fermented — the chemical process that converts sugars to alcohol or organic acids.

Crane’s class is one of the most popular among Hopkins undergraduates during the brief January term called intersession. Though U.S. Census data shows cooking has long been on the decline across the country, the students are among a group of millennials that are showing an interest not just in making food but getting inspiration from a broader “foodie” culture or a do-it-yourself attitude in the kitchen.

The class trains students to be home brewers or vintners or to make their own yogurt. It also teaches them the science behind why some cheese is yellow and others are oozy, when to know whether to send back a bottle of wine, and why honey can be kept on the shelf but milk spoils quickly.

For some students, it’s an outlet to apply lessons of more science-heavy classes in a hands-on way. Sophomore Stephen Brao is studying chemical engineering at Hopkins, but after he dabbled with some home beer-brewing with his father, the class is helping him understand the hobby like a scientist — and giving him some new ideas for career options.

For others who are more focused on the humanities, it’s a chance to learn just enough science.

“I’m in the kitchen a lot,” said Nicola Willoughby, a senior majoring in writing and film. “I thought it would be cool to learn more about it. If you can understand what’s going on when you’re cooking, then you can make changes.”

This month was the second time the class has been offered. Crane, a doctoral student in Hopkins’ Chemistry-Biology Interface program, had taken a similar class while studying biochemistry as an undergrad at the University of Georgia.

More recently, he has tried making his own beer, wine and yogurt, and pitched the class as a way of “demystifying” fermentation.

“I think a lot of people don’t realize it’s really pretty basic science and microbiology and chemistry going on,” he said.

Fermentation is what makes beer and wine boozy, as yeast turns the sugars in grapes or grains into alcohol. But it’s also central to dairy products such as yogurt, buttermilk and kefir, and understanding it properly is vital in ensuring food safety.

In a lecture devoted to the science behind dairy products, Crane explained how milk can be transformed into so many types of food. As a key energy source for infant mammals, it’s high in sugar, fat and water content — properties that also make it a hospitable breeding ground for bacteria.

Raw milk starts to ferment within a few hours left at room temperature, while honey is safe on the shelf because the water it contains is not as accessible to organisms