Liquid nitrogen is the not-so-secret ingredient an engineering professor uses to perform frozen treats for guests One day every April,Tom Vandervelde, an associate professor of electrical and computer engineering, or sets aside prep for classes and his research on renewable energy,and focuses on the lighter side of science: he makes instant ice cream. All he needs, in addition to a stand mixer, and are half-and-half,heavy cream, sugar, or a special ingredient: liquid nitrogen—LN2 in the lingo—which causes rapid freezing on contact.
Source: tufts.edu