Nothing beats smooth, creamy, freshly churned ice cream made from fresh ingredients. Smitten Ice Cream in San Francisco takes it a step further by making ice cream to order with its patented “Brrr” machines, which utilize liquid nitrogen to create its creamy concoctions. Seasonal ingredients are placed into the machine’s bowl along with a dairy base and churned with two metal blades. “Fog” spills out of the bowl as the negative-321-degrees-Fahrenheit liquid is added, and excitement ensues.

While using the sub-freezing properties of liquid nitrogen are very en vogue in the dessert world right now (think flash-frozen chocolate molds and mousse), Smitten doesn’t seek to jump on that bandwagon — only to retain the purity of the dessert. Robyn Fisher, founder of Smitten, says that a lifelong fondness for the frozen treat spurred her journey to create the freshest possible scoop, minus all the “unpronounceable ingredients.” To do that, she thought making ice cream to order would be the way to go, and that liquid nitrogen, which freezes anything “almost instantaneously,” was the fastest way to freeze the ice cream.

“I thought if I could find a way to use technology to bring ice cream back to its pure form by just using the ingredients that needed to be there, I could really make it taste better,” Fisher says.

And given Fisher’s self-proclaimed “maker and tinkerer” nature, much like the many others in the tech-obsessed Bay Area, she drew up plans for prototypes with the help of an engineer for what would become the Brrr machine.

A video posted by le mischievous fox (@jeifox) on

Fisher says that while using liquid nitrogen in ice cream-making isn’t new, it’s difficult to master. Because it acts so quickly and tenaciously due to its extreme low temperature, sticking and clumping can be an issue, creating Dippin’ Dots–style pellets. This meant that Fisher had to find a way to create the smallest ice crystals in the churning process in order to make the smoothest scoop.

“The impetus for creating our own custom ice cream machine was to master that process and churn incredibly smooth, creamy, great-tasting ice cream really quickly so that we could use the freshest and highest-quality ingredients and nothing else,” she says. “We had a breakthrough when we created double-helical mixing blades that essentially allowed us to scrape every surface at all times so that none of the ice cream could clump together while it was churning, which meant that we were able to create the tiniest ice crystals and therefore the smoothest ice cream — all in about 90 seconds from pouring the ingredients in.”

Although Fisher started experimenting with her Kitchen Aid and liquid nitrogen, she doesn’t recommend doing it at home. The end result will certainly be ice cream, but not the best-quality scoop. Liquid nitrogen is also very dangerous for beginners to work with and can result in burned skin and ruined equipment.

“Back in the early days, I once burned the bottoms of my feet because I was wearing socks without shoes and spilled liquid nitrogen, which then absorbed into my socks like water,” she recalls. “Take my word for it — it’s certainly something you should research and understand before trying.”