Inside: Making ice cream is a cool, interactive way to teach chemistry. It makes a perfect science activity for either home school or classroom instruction. Better yet, you end up with yummy, healthier ice cream along with learning some applied chemistry.
Making ice cream is a divine way to teach science. Ice Cream is my weakness. It is a fan favorite with my own kids. We love it as a treat on a hot summer day. Heck, I love its cool sweetness even on a frigid winter day – snug and warm on my sofa though.
Have you ever wondered how that cold, sweet goodness is made from a simple cup of cream? Believe it or not, there is some real science involved in the making of ice cream.
Do you need a lot of advanced equipment? Well, if you’re making thousands of gallons to supply endless supermarkets then ya your equipment might be complex and expensive. You want to make some just for you and the kids? Then read on.
Supplies You Need for Making Ice Cream
Home made ice cream is a healthy alternative to store-bought. Its only got three ingredients. You heard that right – only three and you’ve likely got those ingredients on hand. The supplies to make it you’ve likely also got in your drawers at home as well.
What do you need, you’re asking, to make some ice cream for you and your kids? How about a couple of Ziploc bags – one big and one smaller. Take a look at the picture below.
For the rest you’ll need:
- a half cup or full cup of half-half cream, or full cream if you’re not worried about the calories;
- 1TBS of white sugar;
- 1tsp of vanilla
- enough ice to fill the large bag about 3/4 full;
- 4TBS of salt
If you’re a classroom teacher, making ice cream is super simple and uses the same supplies and instructions.
Making Ice Cream at Home or in the Classroom
How is the ice cream made?
- Put all the food ingredients into the small bag. Zip it up tightly.
- Put the ice and salt in the large bag.
- Now put the small bag with cream mixture inside the large bag.
- Zip the large bag tightly and start shaking that large bag.
You’ll need good, strong-arm muscles for this. If you’re getting your kids to help you might need to take over the bag shaking for a while. Come to think of it, you’ll likely need your kids to take over for you. Shake that bag for 10 or 15 minutes. It’s a long time for shaking and you’ll need patience. Multiple hands to do the work will make the job so much easier. Consider this part of the process a great way to work off some calories before you consume the deliciousness waiting in that small bag.
The Science Behind Ice Cream
Making ice cream looks at the following concepts of science:
- States of matter
For those of us who live in a climate having frigid winters, we’ve seen salt put on the roads during snow or ice storms. Why is this done? Well, the salt mixes with the ice or snow and reduces the freezing point of water. Thus, the ice or snow melts even when the temperature is well below zero. Safer driving conditions are created.
The same principle is used in making ice cream. Cream must be cooled significantly. To create a change of state so liquid cream becomes solid ice cream, the temperature of the cream must be dropped below 0º C or 32º F. When you add salt to the ice, salty water results that is much colder than the freezing point. Shaking the small bag of cream within this briny mixture results in heat from the cream being absorbed into the salty water. Shake long enough and enough heat is removed from the cream to turn it into a solid. Ice cream is the result. Mmmmmm
A Chemistry Experiment for Home School or Classroom
I’ve created a set of worksheets to use in making ice cream a fun science experiment. Your student(s) create a hypothesis and investigate the concepts of changes of state, freezing in particular and the chemistry of solutions. The lab includes materials and a clear procedure to follow. Make sure to have spoons on hand so everyone can taste their experiment once all observations are made and recorded!