Make ice cream without an ice cream maker quickly! A great experiment to really get kids thinking about the food they enjoy.
You will need: .5 cup of cream, ice cubes, 6 tablespoons of salt, the coarser the better, 1 tablespoon of sugar, a small and a large zip-lock bag, food flavoring.
# 1 – Mix together the cream, sugar and flavoring of your choice. The denser the cream the thicker the icecream will be. You can use milk but it won’t be as nice! Pour the mixture into the small zip-lock bag and shut tightly.
# 2 – Fill the large zip-lock bag with ice and the salt. Make sure there is enough room for the small bag. Place the small bag inside the big bag and seal tightly.
# 3 – Squeeze and smoosh the big bag, it will take at least 5 minutes, so perhaps take it in turns! You can feel through the big bag when the cream starts to turn solid. Once you think the cream has thickened enough take the small bag out of the big bag, open up and enjoy!
How what why?! Just like in the winter when we put salt on the roads! Salt lowers the temperature at which water can freeze. So adding the salt to the ice means that inside the bag temperatures can reach -5 degrees Celsius. This is cold enough to cause the cream inside the small bag inside the big bag to freeze. The constant squishing by you means that the ice-cream won’t freeze in a sheet and become crystallised, because you are effectively stirring frozen cream… which is ice cream!