Find out how to make ice cream without using a freezer
For this experiment you'll need...
- A plastic resealable bag
- A smaller plastic resealable bag
- A lot of ice
- Flavoured milk (e.g strawberry, chocolate or banana) or regular milk (with vanilla and sugar)
Find out how to make the ice cream by watching the video below or follwow the instructions underneath the video.
- First take the smaller resealable bag and pour in your flavoured milk.
- Take the larger plastic bag and put in the ice and half a cup of salt.
- Make sure to squeeze the air out of both bags.
- Now seal the smaller bag inside the larger bag.
- Then shake!
- Shake the bag for around 6 minutes.
- Once you're done carefully take the small bag out maybe give it a wash to get the salt off it.
- Then you'll discover that the milk has turned into ice cream!
When salt is added to the ice in your bag it forces the ice to melt. However, for the ice to melt it needs to borrow heat from the environment around it – which is your ingredients. As the ice absorbs the heat from the milkshake, the milkshake get colder, until it freezes and ends up as ice cream. We call this an endothermic reaction.
- Endothermic reaction – An endothermic reaction absorbs heat from its surroundings, causing the temperature of the surroundings to decrease.
Activities and Questions:
Why do we put salt on icy roads?
If an endothermic reaction absorbs heat form the environment, what is an exothermic reaction? Can you think of an example of one?