Ice Cream in a Bag

July 19th is National Ice Cream day! The United States is the second largest consumer of ice cream in the world. At home, you and the kids can make your very own ice cream. It doesn’t take a lot of ingredients nor expensive equipment. It’s quick, easy and virtually mess-free. Download the recipe here.

While you’re shaking your bag of ice cream, you can explain the science behind it. When salt and ice mix, the freezing point of the ice is lowered and the freezing point reached depends on the amount of salt used. The more salt is added, the lower the temperature can get before the saltwater solution freezes. This makes the ice colder than it was before, which is how your ice cream freezes. Rock salt which, with larger crystals, takes longer to dissolve and may result in a smoother ice cream.

The shaking moves the warmer cream mixture from the inside to the outside of the bag so it can freeze evenly. That way you make a smoother product. It also adds air to the final product so it’s fluffed up a little bit.