This fun science project ends with you eating the results – how great is that?
Make your own ice cream in a plastic bag with no freezer required. This project explores freezing point depression – where the freezing point of liquid is lowered by adding another component to it. For example, when salt is added to an icy road it mixes with a small amount of liquid water. This combination reduces the freezing point further and prevents the melting ice from re-freezing. If you mix salt and ice in a bag, the same process makes the ice colder, meaning it can be used to make ice cream as we’re going to do here!
¼ cup of sugar
½ cup of milk
½ cup of whipping cream
2-3 cups of ice
¼ teaspoon vanilla essence
½ to ¾ cup of salt (rock or table will be fine)
Measuring cups and spoons
1 small zip-top freezer bag
1 larger zip-top freezer bag
What happens to the ice as your ingredients start to freeze?
Was there a difference in temperature of the salt and ice mix before and after?
Try it again but is it the same result if you leave out the salt or swap it for something like sugar?
Maybe try swapping the milk for a different type of milk – what happens then?See our Primary Science Course