Summer is raging on and its getting hot out there! Want to cool down with a yummy treat, and still learn a new thing or two? Believe it or not, creating homemade ice cream involves a great deal of chemistry. Put your STEM skills to the test for this chilly science experiment with a sweet result! 

1 cup of half-and-half
2 tablespoons sugar
½ teaspoon of vanilla extract
3 cups ice
1/3 cup kosher salt
Gallon-sized bags
Sandwich-sized bags
Ice cream toppings of your choice

Ice Cream DIY Summer Science

Step One:

Using your sandwich-sized baggie, combine the half-and-half, sugar, and vanilla.

DIY Ice Cream Summer Science

DIY Ice Cream Science

Be sure to combine it well by shaking it, and then squeeze out the extra air and seal it well.

Ice Cream Chemistry: Even though the half-and-half might already be slightly cold, it isn’t enough to make the ice cream take its desired solid form. These three ingredients all need to be cooled down further. But how?

DIY Ice Cream

Step Two:

Place the ice in the gallon-sized baggie and add the salt.

DIY Ice Cream

Ice Cream Chemistry: The salt lowers the temperature at which water freezes. This bag of salt ice will melt even when the temperature is below the normal freezing point of water. This is the same principle in the wintertime when trucks put salt on slick, icy roads.


Step Three:

Place the small bag into the ice-filled bag. Shake it vigorously for 7-10 minutes.

Ice Cream Summer Science

Step Four:

Check ice cream to see if its consistency has hardened.

DIY Ice Cream

Ice Cream Chemistry: You might need a towel or oven mitts when you shake the bag because it becomes so cold. Due to the vigorous shaking and the ice that is now several degrees below freezing, the liquid has been cooled enough to harden it.

If you tried this experiment without the salt, the liquid would have remained in that liquid state simply because the ice wasn’t cold enough. Who knew the most important ingredient in making bagged ice cream would be salt?


Step Five:

Remove from bag, add toppings, and enjoy!

DIY Ice Cream Science

Yum! We love the Summer of Science!

DIY Ice Cream