Liquid Nitrogen Ice Cream
Materials: ★★★ Requires materials not commonly found in school laboratories
Difficulty: ★★☆ Can be done by science teachers
Safety: ★★★ Only to be attempted with adequate safety procedures and trained staff
Categories: Food Science and Nutrition, Liquid Nitrogen
Alternative titles:
Summary
creamy ice cream is made by rapidly freezing a prepared base with liquid nitrogen, creating very small ice crystals that give it a smooth texture.
Procedure
Prepare a vanilla ice cream base using milk, sugar, cornstarch, and vanilla.
Chill the mixture in the refrigerator until cold.
Place the mixture in a metal mixing bowl.
Start a stand mixer on low to medium speed.
Slowly add liquid nitrogen to the bowl a little at a time while mixing.
Continue mixing and adding liquid nitrogen until the mixture thickens into ice cream.
Serve immediately once it reaches the desired consistency.
Links
Variations
Use different ice cream bases such as chocolate or fruit purées.
Add mix-ins (cookies, nuts, or candy) after the ice cream has thickened.
Demonstrate the effect by comparing liquid nitrogen freezing with a traditional freezer method.
Safety Precautions
Safety glasses required.
Wear insulated gloves when handling liquid nitrogen.
Use only in a well-ventilated area to prevent oxygen displacement.
Never touch liquid nitrogen with bare skin - it can cause severe frostbite.
Do not ingest liquid nitrogen directly - only consume food after nitrogen has fully evaporated.
Use a metal or thick-walled mixing bowl to withstand the extreme cold.
Questions to Consider
Why does liquid nitrogen create smoother ice cream compared to traditional freezing?
What happens to water molecules during rapid freezing?
How does the evaporation of liquid nitrogen create the visible fog effect?
Could other cryogenic liquids be used for freezing food safely? Why or why not?
How is this demonstration similar to and different from freezing with dry ice?