Today in Science the Year 5's made Home made ice cream without a freezer. We did this by following the instructions below which only required milk, cream, sugar, ice cubes and salt.
So why the salt?
Scientific Explanation: To make ice cream, the ingredients—typically milk (or half and half) and sugar —need to be cooled down. One way to do this is by using salt. If you live in a cold climate, you may have seen trucks spreading salt and sand on the streets in the wintertime to prevent roads from getting slick after snow or ice. Why is this? The salt lowers the temperature at which water freezes, so with salt ice will melt even when the temperature is below the normal freezing point of water. Technically, the temperature that the salt lowers is called the freezing point. When a freezing point is lowered, such as by adding salt to water, the process is called freezing-point depression.