For making economical ice cream, liquid nitrogen certainly isn’t the best choice. But for the budding chemist looking to make a tasty treat from scratch — and draw a sizable crowd on campus while doing it — it beats plain old ice any day.
“It’s a rather expensive way to make ice cream, but it turns out to be quite good,” said Murray Gibson, dean of the College of Science, who sampled ice cream whipped up on Friday afternoon by students in Northeastern’s chapter of the American Chemical Society.
At 321 degrees below zero Fahrenheit — 77 Kelvin — when liquid nitrogen hits the cream and other ingredients, “it immediately creates crystals,” said sophomore Justin Roberts, the club’s vice president. “All it’s doing is freezing the cream really quickly.” The liquid nitrogen does its work in about 10 minutes, far faster than traditional methods.
The liquid nitrogen quickly evaporates, creating a cloud that looks like smoke. That vapor cloud drew passersby on Krentzman Quad who might otherwise be looking to start their weekend early on a warm Friday afternoon.
“It tastes different from store bought ice cream,” Roberts said, sampling a gooey scoop of vanilla. “It’s a lot more like what you’d make a home.”
The start-of-the-semester event was inspired by a similar one held last year for first-year chemistry students.
“We did it last year for the department’s new freshmen and it really went well, so this year we wanted to open it up to the whole school,” said Vicki Berger, a junior chemistry major and the club’s treasurer.
Even though the main draw was the ice cream made with liquid nitrogen, the budding scientists realized that the process wasn’t fast enough to meet demand on campus. But how does one procure ice cream that’s ready to scoop even faster than the batch made with liquid nitrogen?
Easy — buy it at the supermarket.