Making ice cream in a bag is one of those thrilling examples of when the scientific and culinary worlds collide and merge, which is one of my favorite things about when they do. It is a simple STEM exercise that may be done to enjoy yourself, your children, or your friends, not to mention that giving it a good shake and watching what develops is just enjoyable.

But how exactly does it operate? Why does adding salt and ice to the cream mixture create such a mystical and unforgettable adventure? We are about to reveal the science that goes into creating ice cream in a bag, so hold on to your spoons!

An endothermic reaction serves as the foundation for creating ice cream in a bag, which is the most fundamental aspect of the method. The temperature of the solution is lowered when salt is added to ice, as salt has a cooling effect. To put it another way, the process by which the salt dissolves in the ice necessitates heat, which in turn causes the ambient temperature to drop. Because of this reaction, a supercooled solution is produced, a solution with a temperature lower than the freezing point of water.

So, how does any of this pertain to the ingredients for the ice cream? When you put the cream mixture into a smaller bag, seal it, and place it inside a giant bag of salt and ice, the solution surrounding the smaller bag will get cold enough to freeze the mixture within the smaller bag. You then transform the liquid into your preferred sweet by shaking the bags vigorously, which requires little effort.

Now, onto the recipe. Here’s what you’ll need to make two small servings of vanilla ice cream:

-1 cup of any milk or half-and-half
-2 Tbsp. sugar
-1/2 tsp. vanilla extract
-3 cups (doesn’t need to be exact) of ice
-1/3 cup salt
-A sandwich-sized plastic resealable bag
-A gallon-sized plastic resealable bag
-Gloves

First, mix the milk, sugar, and vanilla in the small bag. Squeeze out the air and seal. Next, mix the ice and salt in the large plastic bag. Place the small bag into the big bag and shake hard for 5-7 minutes or until the milk mixture is frozen. Be sure to wear gloves because the bag will get very cold!

Experiment with other ingredients to make other flavors, such as adding powdered chocolate for chocolate ice cream or chunks of your favorite candy or fruit to make it more delicious and fun.

Making ice cream in a bag is a terrific STEM activity that is fun, educational, and delicious. It doesn’t matter if you’re still a kid at heart or if you’re trying to find a way to entertain your kids. This is an activity that anyone can enjoy, as it involves both the application of science (in the form of making the solution cold enough to freeze the ice cream mix) and the application of creativity (in the form of adding your own flavors and toppings). Put on some gloves and take a spoon, give it a good shake, and then dig into the delicious fruit of your labor.