Ice Cream!

MATERIALS

• I cup half & half

• ½ cup Kosher salt

• 2 tablespoons sugar

• ½ teaspoon vanilla extract

• 1 pint-sized ziplock bag (small)

• 1 gallon-sized ziplock bag (big)

• Some ice cubes

LET’S GET STARTED!

1. Pour the half & half, sugar, and vanilla extract all into the pint-sized ziplock bag

2. Make sure you zip up the bag super tight so it won’t spill

3. Fill the gallon-sized bag halfway with ice cubes and add the ½ cup of salt

4. Very gently put the smaller bag into the larger bag with the ice cubes and zip up the larger bag (if it starts leaking raise your hand!)

5. Shake, shake, shake!!! Shake the bag for 5-10 minutes, until the ice cream starts to firm up

6. Open up the bags, grab a spoon, and you are done! Enjoy your very own handmade ice cream!

THE SCIENCE BEHIND ICE CREAM :)

As you know, matter has three states: solid, liquid, and gas. At 0℃, water usually changes from its liquid form to its solid form, ice. Thus we can call this temperature the freezing point of water. However, salts and sugars are known as freezing point depressors, meaning they lower the freezing point of water so that it freezes at a lower temperature. When salt is added to ice, some of the ice melts because it absorbs energy from the surrounding heat. In this case, the heat is coming from the warm cream mixture. After adding salt, the water in the milk is able to cool down because the heat of the cream is being absorbed by the ice outside the bag, forming the slush consistency that makes up ice cream.