I Scream, You Scream, We All SCREAM!!!

There is nothing better than a delicious bowl of ice cream on a hot summer day, and nothing more fun than making it yourself!  I am not talking about the "old fashioned" way, but the "scientific" way where you can see the ice cream being formed and get to explain to your little ones why this liquid mush is turning into a delicious frozen treat!

Materials
1/2 c half and half
1 tsp sugar
1/4 tsp vanilla
***optional 1/4 tsp additional flavoring (strawberry extract, banana extract, chocolate extract, etc-all found in the same aisle of the market where vanilla extract is)***
1/4 c kosher salt or ice cream salt
2 gallon double zipper Ziplock bags
2 quart double zipper Ziplock bags
1/2 c ice

Procedure

• Assemble bags by placing one gallon Ziplock bag inside of the other, set aside.  Place one quart Ziplock bag inside of the other.  Pour the half and half, sugar, vanilla (and if using, optional flavoring) into the inside of the inner quart Ziplock bag.  Zip both the inside bag and the outside bag and set aside.
• Put ice and salt in the inside of the inner gallon Ziplock bag, place zipped, small bag inside with ice/salt mixture.  Zip up the large gallon Ziplock bags and shake for about 5 to 10 minutes.  The more vigorously you shake the colder the bag will get and the sooner you will have ice cream!
• Take very inner bag out, wipe off to avoid any salt, grab a spoon and enjoy!  If you want, add any toppings you want!

Explanation: Adding salt to ice makes the ice (water) go from a pure substance-just water, to a mixture, so it's freezing point changes, it lowers and becomes a liquid once again, as a result it loses heat energy becoming even colder, allowing the contents of the liquid ice cream mixture to go from a liquid to a solid!  The more that you shook the bag, the more water that you exposed to the salt and the more rapidly you decreased the temperature allowing ice cream to form!  See, isn't science fun?!