You can use liquid nitrogen to make ice cream pretty much instantly. This makes a nice cryogenics or phase change demonstration. It's also just plain fun. This recipe is for strawberry ice cream. If you omit the strawberries, you can add a bit of vanilla for vanilla ice cream or some chocolate syrup for chocolate ice cream. Feel free to experiment!
Difficulty: Average
Time Required: Minutes
HERE'S HOW
This recipe makes a half gallon of strawberry ice cream. First, mix the cream, half-and-half, and sugar in the bowl using the wire whisk. Continue mixing until the sugar has dissolved.
If you are making vanilla or chocolate ice cream, whisk in vanilla or chocolate syrup now. Add any other liquid flavorings you might want.
Put on your gloves and goggles. Pour a small amount of liquid nitrogen directly into the bowl with the ice cream ingredients. Continue to stir the ice cream, while slowly adding more liquid nitrogen. As soon as the cream base starts to thicken, add the mashed strawberries. Stir vigorously.
When the ice cream becomes too thick for the whisk, switch to the wooden spoon. As it hardens more, remove the spoon and just pour the remaining liquid nitrogen onto the ice cream to fully harden it.
Allow the excess liquid nitrogen to boil off before serving the ice cream.
TIPS
The mix of whipping cream and half-and-half helps to make a very creamy ice cream with small crystals, that freezes quickly.
Don't touch liquid nitrogen or store it in a closed container!
If the ice cream begins to melt before everyone is served, simply add more liquid nitrogen.
A large plastic mug with a handle is good for pouring the liquid nitrogen. If you use a metal container, be sure to wear gloves.
I'm told a cordless drill with a mixing attachment is even better than a whisk and wooden spoon. If you have power tools, go for it!
WHAT YOU NEED:
5 or more liters of liquid nitrogen
Gloves and goggles recommended
Large plastic or stainless steel punch bowl or salad bowl
4 cups heavy cream (whipping cream)
1-1/2 cups half-and-half
1-3/4 cups sugar
1 quart mashed fresh strawberries or thawed frozen berries
Additional half cup of sugar if you are using unsweetened berries
Wooden spoon
Wire whisk