Thursday, April 1, 2010

Super Science

My oldest says he's, "a future scientist."
He loves to do experiments.
Here is one we did last summer.
Fun & Delicious!... & easy!

Ice Cream In A Bag

quart & gallon zipper bags
1/2 cup milk
1 tbsp sugar
1/2 tsp vanilla extract
6 tbsp salt (using Rock Salt is quicker, but I've found that regular salt works just fine)
2 cups ice cubes (1 ice cube tray worth)
*makes about 1 scoop of ice cream*
Mix vanilla extract, sugar, and milk. Pour into smaller size bag and seal closed. Put ice cubes and salt into larger size bag. Place the bag with milk mixture into the ice mixture bag and seal closed.

Make sure bags are sealed COMPLETELY.  Shake, shake, shake. Be careful not to get too rough or the salt my leak into the ice cream. You will feel the ice cream getting thicker. It takes about 5-10 minutes.

When ice cream is desired thickness, remove bag from ice mixture. Wipe the outside of bag with to remove salt, but DON'T rinse the bag under water or the ice cream will begin to melt.

Eat plain, or add our favorite, chocolate sandwich cookie pieces & chocolate syrup.

Here's WHY it works: (mine always ask "why?", do your's?)
"Ice has to absorb energy in order to melt, changing the phase of water from a solid to a liquid. When you use ice to cool the ingredients for ice cream, the energy is absorbed from the ingredients and from the outside environment (like your hands, if you are holding the baggie of ice!). When you add salt to the ice, it lowers the freezing point of the ice, so even more energy has to be absorbed from the environment in order for the ice to melt. This makes the ice colder than it was before, which is how your ice cream freezes. Ideally, you would make your ice cream using Rock Salt, which is just salt sold as large crystals instead of the small crystals you see in table salt. The larger crystals take more time to dissolve in the water around the ice, which allows for even cooling of the ice cream."

1 comment:

  1. this is great.

    i love your idea for a blog site here.

    i'll feature this on one of my spotlight Saturdays, for sure!


Comments & Ideas Welcome!