Making ice cream is a process that involves two states of matter, liquid to solid. It’s a process called freezing. Using rock salt lowers the freezing point of water, making it extremely cold to freeze your ice cream! The colder it is, the slower the molecules of a substance move and they become very close together, making a solid. Try this experiment below and enjoy eating your results!
Materials Needed
- 1 cup whole milk
- 1 cup whipping cream
- ½ cup sugar
- ½ tablespoon vanilla
- Ice
- ¾ to 1 cup rock salt
- 1 large empty coffee can with lid
- 1 small empty (clean) coffee can with lid
What to Do
- Place milk, cream, sugar, and vanilla in the small coffee can. Stir it for about 30 seconds, then seal it with the lid. (Hint: You may want to use duct tape to help seal the lid shut so your ice cream mixture doesn’t leak out.)
- Place the small coffee can into the large coffee can.
- Pack ice around the small can.
- Sprinkle ¾ cup of rock salt around the ice.
- Seal the large can with the lid.
- Roll the can back and forth across the floor or a table for 10 minutes. (Having a partner will be helpful to do this)
- After the 10 minutes is up, open the cans, stir the ice cream and scrape off the sides – then reseal the small can. (Caution: If the salt water in the big can gets into the small can, your ice cream will be ruined)
