Liquid Nitrogen Ice Cream

It's a relatively simple recipe, and even easier to prepare.

The basic recipe (with variations to your taste) is:

1. 6 cups of heavy cream/half-and-half/milk
   (The first recipe I used had 4:2 Heavy cream to half-and-half --this left a kind of "waxy" residue on the spoons and my tongue. I then used 4:2 half-and-half to heavy cream and it came out much better -- your tastes may differ.)
2. 2 cups of sugar
   (This amount will be lower if you add a sweet / syrupy flavor like chocolate syrup etc. Back the recipe down by .25 to .33 cups in this case
3. One tablespoon of vanilla extract (again, to taste)
   (One thing to add before you "freeze" the ice cream. If you have a fruit mix, chocolate chips or some other sort of thing that you want suspended in the ice cream, make sure you add it after you freeze it a bit, or all the pieces will sink to the bottom of your ice cream.)

Now to freeze it . . . Get a *large* metal bowl and a wooden (or other sort of material that won't break when cooled to very low temperatures) spoon and pour the mixture in. Add ~ 1-2 liters of the LN2 and stir vigorously. (This will be very impressive to the kids as it will look like you're stirring a cauldron of witch's brew!) If you have something to add to the ice cream (fruit, nuts, etc.) get the ice cream cold enough until it just begins to lose it's shiny appearance, then add. From here just keep adding the LN2 until the ice cream is the desired consistency.

Serve immediately! You can get ideas for flavors and items to add by looking in a cook book that has regular hand-churn ice cream recipes and adapting them to this recipe/freezing method. -Kevin

From:
Kevin M. Dudley
Lab Manager UNC Physics & Astronomy