Keeping Cool With Some Yummy Science!

As the temperatures climb higher and higher and summer sets in, here's how you can make your own delicious treat to cool off. And it's scientific too!

Materials:

• 1/2 cup milk (whole or 2% works best)
• 1/2 cup heavy cream (optional)
• 1/2 tsp vanilla
• 1 TBS sugar
• 4 cups crushed ice
• 4 TBS salt
• 2 quart-size plastic bags
• 1 gallon-size freezer bag
• gloves or mittens to keep your hands warm
• towels (this can get a bit watery and messy)
• masking or duct tape
• Scissors

Procedure:

1. In one of the quart-size plastic bags mix the milk, vanilla and sugar (mix until sugar dissolves.)
2. Release as much air from the bag as you can. (You don't want the bag to pop while mixing!)
3. Close the bag and seal the top with tape.
4. Put the bag of ingredients into the other quart-size bag, remove the air and seal the top with tape. 
5. Set your mixture bag inside of the gallon-size bag and fill with ice.
6. Sprinkle salt on top of the ice, squeeze out the air and seal the bag with tape. 
7. Put your gloves or mittens on. It's going to get COLD!
8. For 5 minutes shake, knead and gently squeeze the bag moving he mixture around. 
9. Once you feel the mixture begin to solidify continue for 1-2 minutes.
10. Cut the tape from the baggies and carefully remove the ice cream. 
11. Dig In!!!

What's the Science?

The salt in the bag causes the ice to melt. This creates a "brine." Brine is a solution of salt in water. Brine is sometimes used to preserve vegetables, fruit or fish, but in this case we used the brine solution to absorb the heat from the ice cream mix. As the brine solution gradually lowered the temperature from the mix it began to freeze. In order to get the ice cream mixture to freeze, we must drop the temperature below 32 degrees. By adding the salt we are able to lower the freezing temperature to around 27 degrees and VIOLA... you get some yummy ice cream.