Use the power of science to make homemade ice cream in a bag! This sweet treat is ready in less than 10 minutes without requiring any special equipment or ingredients. Making homemade ice cream is a tasty addition to our growing list of fun and simple kitchen science experiments.
Making Homemade Ice Cream
*This post contains affiliate links. Please see our disclosure policy.
We headed to the kitchen to gather the following supplies:
- One small Ziploc baggie (quart or sandwich size)
- 1/2 cup of milk (whole milk or cream work best, but any variety will be fine)
- 1 Tbsp. sugar
- 1/4 tsp. vanilla
- One gallon-size Ziploc bag
- 8-10 cups of ice
- 6 Tbsp. salt
Once we had all of our supplies ready we followed these directions to make our delicious science ice cream in a bag:
- Add milk, sugar, and vanilla to the small baggie. Seal the bag, being careful to release excess air.
- Add ice and salt to the bigger baggie.
- Place the small baggie into the large bag of ice and salt. Seal the large bag.
- Shake for about 5 minutes or until the milk mixture turns into a soft solid.
- CAREFULLY open up the large bag, remove the small bag and rinse it off quickly and thoroughly in cold water (pay special attention to rinse off the opening of the baggie). Without this step salt may get into the ice cream, which completely spoils it! (I know from experience.)
- Either grab a spoon and eat your ice cream right out of the bag, or pour your ice cream into a bowl. Top with sprinkles and toppings of your choice and enjoy!
The Science of Homemade Ice Cream
To make any variety of homemade ice cream, milk needs to be partially frozen. Putting milk directly in the freezer and leaving it there makes the milk freeze solid, which is no good. When you try to eat the ice cream it’s no longer creamy and smooth. It gets all icy and crystal-y and weird.
Water freezes at 32°F, but because milk contains proteins and fat it freezes at a lower temperature. This means that trying to freeze milk with ice cubes won’t work either. You need to add a special ingredient to your ice cubes to make a mixture that is even colder than ice alone. Ready for the secret ingredient? I’ll give you a few clues. It’s white. It’s something almost everyone has in their kitchen. It tastes yummy on popcorn with butter. It’s….SALT!
We talked about the magical science of how salt and ice cubes work when we did our Fishing for Ice experiment and when we made our delicious fruity slush. When salt is added to ice, it lowers the freezing point of the ice, making it melt. This leaves a salty-icy-watery mixture that is much colder than 32°F. The temperature of the salty mixture is close to 0°F! (You can verify this with a thermometer.) This temperature is cold enough to freeze milk into homemade ice cream in less than 10 minutes without freezing it solid.

Math Inspired Creative Drawing Ideas for Kids from Handmade Kids Art
Magnetic Slime Science Play from Little Bins for Little Hands
Fizzing Green Eggs Science for Preschool from Preschool Powol Packets
Hey didn’t know we could teach science while making ice cream!
Unfortunately ice cream is the only thing I don’t allow him to eat! Both he and I are prone to cough , since we shifted to a high allergy zone two years back! Imagine not having ice cream for two years! I miss it 🙁
Oh this so appeals to the geek in me! It’s awesome. Thanks so much for sharing with the #pinitparty. Have pinned 🙂
This is awesome! So informative. Cannot wait to show my kiddos. Beautiful photos as well.
Thank you so much! So glad you stopped by 🙂
Can’t wait to try this with the kids! Thanks for sharing! I’ll be sharing this on Facebook and Pinterest.
That looks great fun, great science too!
Thanks for linking up to Tuesday Tutorials.
I remember making ice cream like this many moons ago! Such fun, and you get a yummy treat at the end. 🙂 I hope you can stop on by and share this or any other recipe with us on Five Friday Finds!
I will, thank you!!
This sounds yummy! What a delicious way to learn about the science of salt!
Thank you for stopping by the Thoughtful Spot Weekly Blog Hop this week. We hope to see you drop by our neck of the woods next week!
Such a fun treat! I just wanted to let you know you’re featured this week on Five Friday Finds! I’m looking forward to what you share this week. 🙂