The Chemistry of Yum

Most recipes for homemade ice cream require four or five hours in the kitchen. In what has become a Vassar tradition, a couple of chemistry majors complete the task every week in four or five minutes, then give it away to fellow students. Their not-so-secret ingredient: liquid nitrogen.

Ice cream chefs Bevan Whitehead ’19 and Jaimeson Bukacek-Frazier ’19 celebrated the final day of fall-semester classes by serving up a batch of blueberry-lemon ice cream in the atrium of the Bridge for Laboratory Sciences. They blended a mixture of milk, cream, Egg Beaters, vanilla extract, sugar, lemon juice, and blueberries in a large metal bowl. Then Bukacek-Frazier poured the liquid nitrogen (-195.8°C, or about -320°F) into the mixture. Clouds of vaporous fog billowed over the top of the bowl as Whitehead continued to stir. After the fog cleared a minute or two later, the ice cream was served in small paper cups to about two dozen students who had gathered to watch the show.

Four-minutes, start to finish: The final product!

Anya Scott-Wallace ’20, a psychology and biology double major from Bel Air, MD, was one of the first in line to sample the chemistry majors’ wares. “I had some last spring, but this is the first time this semester I’ve been able to get some,” Scott-Wallace said. “It’s really good.”

Esperanza Garcia ’20 (left) and Anya Scott-Wallace ’20 savor the blueberry-lemon treat.

Whitehead said he attended a meeting of chemistry majors last semester when volunteers were being recruited for various tasks in the department. “I had the choice of serving on some committee or making the ice cream,” he said. “It was a no-brainer.”

Whitehead and Bukacek-Frazier are the latest in a long line of chemistry majors who have been making liquid nitrogen ice cream since 2003, when chemistry professor Christopher Smart first hatched the idea. “I used to do demonstrations at Chemistry Department meetings and in local elementary schools, so when I became chair of the department, I started it as a weekly event, and the students soon took over,” Smart said.

Liquid nitrogen ice cream chefs Bevan Whitehead ’19 (left) and Jaimeson Bukacek-Frazier ’19 (center) with the man who started it all, chemistry professor Christopher Smart.

The ice cream chefs soon began experimenting with various fruits and other ingredients—one made with Earl Gray tea is currently the most popular—and in 2008, Smart and his students started to write the recipes down in a book he keeps in the Chemistry Department office. The book currently contains about 50 recipes. “I’m thinking of contacting the American Chemical Society and asking them if they’d like to publish our recipes in a pamphlet,” Smart said. “I think I can say with certainty that Vassar’s Chemistry Department has more liquid nitrogen ice cream recipes than anyone else in the world.”

Bukacek-Frazier said brightening a fellow student’s day with a cup of liquid nitrogen ice cream has been one of the highlights of his time at Vassar. “It’s probably the best job on campus,” he said.