Liquid Nitrogen Ice Cream

DESCRIPTION:
Liquid nitrogen is -196˚C and quickly freezes the ingredients into ice cream. The nitrogen boils out leaving deliciously creamy ice cream. The “fog” that we see is condensed water vapor though, not nitrogen gas.

TOPICS COVERED:
cryogenics
vaporization
freezing
condensation
mixtures
physical change

MATERIALS NEEDED:
– 8 quart metal bowl
– long handled wooden or plastic spoon
– oven mitt
– 2 quarts heavy whipping cream
– ½ gallon milk
– 2 ⅔ cups of sugar
– 5 tbsns vanilla extract
– liquid nitrogen
– cups, spoons, napkins for eating ice cream

PROCEDURE:
1. Add all ingredients to the bowl
2. Gradually stir in liquid nitrogen until the ice cream is of the desired consistency

ADDITIONAL COMMENTS:
Crushed Oreos can be added to make cookies & cream. Use the oven mitt to hold the bowl, because it will become very cold!

SAFETY:
Liquid nitrogen can freeze tissue, causing skin damage. Caution should be taken and goggles worn at all times. Additionally, the bowl and spoon used for this should not be used for any chemicals and should be stored in a food safe environment to prevent any contamination.

Handout

This problem set practices unit conversions, and can be helpful for students to see how quantities they are familiar with translate into SI units.