Ice Cream in a Bag

Today we made homemade ice cream as an experiment in kinetic energy. The students added their kinetic energy (energy of movement) to their experiments to make yummy homemade ice cream. We also learned that salt lowers the freezing point of water, which allows it to get colder than ice (28 degrees Celsius). The super cold water and ice mixture causes the liquid milk mixture to freeze and become solid ice cream. At the end they got to enjoy a sweet treat!

Recipe and directions for this experiment:

1 gallon ziploc bag
1 quart ziploc bag
4 cups ice
1/4 cup rock salt
1 cup whole milk
1 teaspoon vanilla extract
2 tablespoons sugar
cups and spoons

1. Pour the milk, vanilla, and sugar into the small ziploc bag. Squeeze as much air out as possible and seal the bag carefully.
2. Place the small ziploc bag down into the large bag. Cover with the ice and salt. Seal the large bag tightly.
3. Shake, toss, and flip the "Ice cream machine" for five to ten minutes. If the bag gets too cold to handle, wrap it with a towel or pass it from person to person.
4. Open both bags and spoon the ice cream into small cups.