Fun With STEM Activities: Ice Cream in a Bag

If you are going to choose one STEM activity to do with your preschooler, I think we can all agree that making ice cream is a pretty exciting project for both you and your little one. With a few simple ingredients and some vigorous shaking, you can teach your toddler how to make ice cream, the science behind it, and have a special treat for the both of you to enjoy. Read on to learn more about how to make ice cream in a bag and what makes this activity a STEM activity.

I love when you can combine science with a delicious edible treat.

So I was excited to find a STEM activity that involved making ice cream in a bag. It seems like magic, but there is real science happening inside the bag! The salt and ice make a solution that gets cold enough to freeze your milk.


How To Make Ice Cream In A Bag


How to Make Ice Cream in a Bag - KTeacherTiff

Making ice cream does not require a special machine or rock salt. In this recipe, we use ice and regular table salt combined with some shaking to create the perfect environment for ice cream to freeze.


  • ½ cup half and half
  • ¼ tsp vanilla extract
  • 1 Tbsp sugar
  • 3 cups of ice
  • ½ table or kosher salt
  • Toppings (optional)


  1. Place your ice and salt in a gallon-sized zip-lock bag.
  2. Mix your half and half, vanilla extract, and sugar in a separate quart-sized zip-lock bag.
  3. Seal the quart-sized bag, place it inside of the gallon-sized bag, and then seal the gallon-sized bag.
  4. While wearing gloves (this is going to get cold!) mix the bag for about five minutes.
  5. You’ll know your ice cream is ready when it has begun to solidify.

What Makes Ice Cream In A Bag A STEM Project?

When you mix together ice and salt, a chemical reaction occurs that lowers the freezing point of water. The result is a release of energy due to the water changing from a solid to liquid state resulting in a colder environment which freezes the ice cream. It is the same scientific process that allows us to de-ice our sidewalks with rock salt in the winter.

The shaking of the bag promotes the even distribution of energy throughout the ice cream mixture, ensuring that the ice cream freezes at the same rate throughout, rather than unevenly. This also helps the ice cream to be creamer, as the continuous shaking keeps the mixture homogeneous rather than separating into its counterparts which would all freeze at different rates and into different molecular structures, which would result in an icy texture.

While you may not find the need to explain every aspect of the science behind how and why ice and salt can make ice cream to a toddler or preschooler, these are all details that you can keep in your back pocket as your child grows, and makes this experiment ideal for children of all ages.


If you’re searching for a quality, education preschool for your little one in Delaware County, reach out to Rising Stride to schedule a tour of our child care facilities today.