Make Ice Cream in a Bag

Introduction

Everyone loves to eat ice cream, so why not make your own! This simple recipe takes nothing more than what is already in your kitchen, and is fun and educational! Learn the science behind how ice cream is made, and then enjoy!

Purpose

• To reinforce the curriculum in Science
• To Participate in science activities and discussion

Time

About 10 minutes.

Materials

• 1⁄2 cup milk
• 1⁄2 teaspoon vanilla
• 1 tablespoon sugar
• 4 cups ice (crushed preferred)
• 4 tablespoons salt
• 2 quart size Ziploc bags
• 1 gallon size Ziploc freezer bag
• A hand towel or gloves
• Any other ingredients desired for enjoying the ice cream: sprinkles, chocolate syrup, etc.

Directions

• Mix the milk, vanilla and sugar together in a quart size bag. Seal tightly, allowing as little air in the bag as possible.
• Place the bag inside the other quart size bag, allowing as little air into the bag as possible. The purpose of the double bag is to prevent salt and ice leaking into the ice cream.
• Put the double bags inside the gallon size bag, fill the bag with ice, then sprinkle salt on top. Seal the bag tightly, allowing as little air in the bag as possible.
• Wrap the bag in a towel or put gloves on.
• Shake and massage the bag, making sure the ice surrounds the cream mixture.
• Continue for five to eight minutes and then eat!

Other Information and Resources

• This recipe can also be done in a coffee can, and can be doubled or tripled since the can holds more:

• Put the mixture in a standard size coffee can and seal with the lid.
• Place the standard size can in a larger 'economy size' can and pack the large can with ice and salt. Seal with the lid.
• Roll the can back and forth until the ice cream is set.
• The time required to set the mixture will vary depending on the number of servings in the can.

• The science behind it:

Just like we use salt on icy roads in the winter, salt mixed with ice in this case also causes the ice to melt. When salt comes into contact with ice, the freezing point of the ice is lowered. Water will normally freeze at 32 degrees F. A 10% salt solution freezes at 20 degrees F, and a 20% solution freezes at 2 degrees F. By lowering the temperature at which ice is frozen, we are able to create an environment in which the milk mixture can freeze at a temperature below 32 degrees F into ice cream.