Quiz: What keeps us safe in the winter and makes ice cream in the summer?
Who doesn't like homemade ice cream? It sure is nice being able to make ice cream while sitting on your back porch but have you ever wondered how that happens? The answer is the same as if your question was - how do we keep the roads from icing over in the winter?
We all know water freezes at 32° F, right? That's true - unless the ice comes into contact with salt. Then the freezing point of ice is lowered.
A 10% salt solution freezes at 20° and a 20% solution freezes at 2°.
In the winter, putting salt on the road lowers the temperature at which water freezes so the ice with salt on it will melt even though the temp is below freezing. When you're making ice cream, you want to the temperature to be lower than 32° so it will form into a delicious treat.
Salt mixed with ice creates a brine with a temperature lower than 32° so your ice cream is able to freeze.
Here's a little experiment to test it out. Put two trays of water in the freezer. Fill one with plain water and the other with salt water. The plain water will freeze first.
Want to make your own ice cream even if you don't have an ice cream maker?
All you need is an ice cream mixture, a few plastic bags, some ice cubes and salt. Click here for a recipe from "Our State Magazine" for a special North Carolina version of strawberry ice cream.