How does cooling materials change them?

What do you get when you mix 1 teaspoon of sugar, half cup of milk and a drop of vanilla? The Grade 2s will tell you they discovered an easy way to make ice cream! We investigated why some ice cream was frozen and others were more of a liquid. Maybe there was not enough insulation? Maybe we did not shake it long enough? Did we need to add more rock salt to the ice? We were very inquisitive and sweet scientists today! ;)