Saturday, September 17, 2011

Icecream in a Bag

Customary Measurement:                                                       Metric Measurement:
1 gallon ziploc bag                                                                   1 large ziploc bag
1 quart ziploc bag (heavy duty)                                                1 small ziploc bag
4 cups ice                                                                               1 liter ice
1/4 cup salt                                                                             60 ml salt
1 cup whole milk                                                                    250 ml whole milk
1 teaspoon vanilla extract                                                        5 ml vanilla extract
2 tablespoons sugar                                                                30 ml sugar
cups and spoons cups and spoons

1. Pour the milk, vanilla extract, 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 5 to 10 minutes. If the bag
gets too cold to handle, wrap it with a towel or pass it from person to
person. Don’t open the large bag to check the ice cream because it may not
seal properly afterwards.
4. Open both bags and spoon the ice cream into small cups. Enjoy!

Flavor variations:

1. Substitute other extract flavors for the vanilla.
2. Omit the vanilla and half the sugar. Add strawberry or chocolate syrup to
the milk mixture.

Science Explanation:

The salt lowers the freezing point of the water which allows it to get colder
than ice (about 28 degrees). This super-cold water and ice mixture causes
the liquid milk mixture to freeze and become solid.
Created by Laura Candler - Teaching Resources -

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