Do you like ice cream? I mean who doesn’t…
Learn how to make ice cream at home with this experiment and discover how it works!
Materials:
Measuring spoons, measuring cups, 1 tbsp sugar, ½ cup half-and-half cream (OR milk OR heavy whipping cream), ¼ teaspoon vanilla extract, ½ cup salt, 4 cups ice cubes, resealable bags (gallon and pint-sized), a towel, timer.
Time Estimated:
15 minutes
Directions:
In the pint-sized bag, pour in the following (in their full amounts):
Sugar
Half-and-half cream (OR milk OR heavy whipping cream)
Vanilla extract
Seal the bag as tight as you can.
In the gallon-sized bag, pour in the following:
Ice cubes
Salt
Place the smaller bag inside the larger bag and seal the larger bag. Make sure that both bags are sealed as tight as possible!
Wrap the large bag with a small towel and shake for five minutes.
Every minute or so, be sure to check that everything is still sealed tight.
After the five minutes is over, remove the smaller bag from the larger one and enjoy your freshly made ice cream!
(Optional) Try the experiment again WITHOUT adding salt to the ice to see if you are still able to make ice cream!
Think Like a Scientist:
What caused the liquid to change its consistency?
How did the ingredients combine and change during the shaking process?
Why was salt added to the ice? Was it a necessary ingredient?
How It Works:
In today’s experiment, you learned about food science!
If you think about it, there is a lot of science behind cooking processes, and not just with ice cream! There is even a group of dedicated scientists, called molecular gastronomists, who focus on the chemical and physical structures of food. For example, they have found a way to make apple juice into tiny little bubbles, vegetables into spaghetti noodles, olive oil into caviar, and other cool food transformations!
The simple explanation for this experiment's transformation is that the salt decreases the temperature of the ice, lowering it from cold to freezing! Therefore, the more salt that is added to the ice, the lower the freezing temperature becomes. This means that the ice is able to get much colder than just regular ice! To put this into perspective, water freezes at a temperature of 0º Celsius (32º Fahrenheit). When salt is added, water only freezes at temperatures below 0º Celsius (32º Fahrenheit). This explains why some of the ice melts once the salt is added. The lower the freezing temperature, the colder the ice can become before it freezes.
For the ice to melt, however, it has to absorb heat from its surroundings (i.e. the liquid ice cream mixture in the smaller bag). The mixing process helps with this heat transfer. Once the ice pulls the heat away from the liquid, the liquid can transform into creamy, frozen ice cream!
If you’ve ever visited places where it snows, this is how they keep the roads maintained: they add salt to lower the freezing temperature so that the roads are covered with water instead of snow. This keeps the roads less slippery at lower temperatures!
This experiment is designed for you to make as many batches of ice cream as you would like. Try to experiment and make new flavors by topping your finished product with things like peanut butter, strawberries, chocolate, cookies, or even your favorite cereal!
Looking for more fun at home STEM activities for your young scientist? Check out our workbook full of exciting science experiments and empowering activities!
