As a mother, grandmother, and ex-Scout leader for both boys and girls, I’ve used variations of the plastic bag ice cream makers for decades and I can truly say that this activity is always a winner.
The most important tip that I can give anyone who is getting ready to try this is to make sure you have enough time. It always takes longer than you think to get everyone’s bags prepared and it certainly takes longer for the ice cream to freeze than what everyone posts.
Plastic Bag Ice Cream Maker Tips
Don’t buy cheap baggies. Make sure you buy the thickest “freezer” style bags that you can so you don’t end up will holes in the bag. And don’t get the little plastic slider close…they generally leak.
Also…don’t believe that you can get all the ingredients in the sandwich bag, and then the quart for the outside. If you try and skimp on this I guarantee that at least one child will rip through their bag. Not that it won’t happen anyway—it’s just more likely if the bags are smaller than suggested.
Plastic Bag Ice Cream Recipe
The ingredients listed below are for each person to make their own ice cream. So if you have ten people making ice cream, please times the individual amounts by ten.
- Milk – ½ cup
- Vanilla – ½ teaspoon
- Sugar – 1 tablespoon
- Mix it Up – If you want to add just a bit of chocolate syrup, mashed banana or other fruit you can do that. It really won’t take more than a tablespoon of anything to flavor the ice cream. Adding fruit or chocolate will also increase the time it takes for the ice cream to freeze.
- Crushed ice – 4 cups (Rather than buy cubed ice, this will work better if you can get someone that has crushed ice for drinks sell you a couple of bags.)
- Salt – 4 tablespoons
- Zip-loc bags – 2 quart size freezer bags and 1 gallon size freezer bag per person
Tip: Use gloves or a small towel for each individual to help keep the child’s hands from freezing.
Putting It Together
The first step is to combine the milk, vanilla, and sugar together in one of the quart size freezer bags. This works better if kids work in pairs, one holding – one pouring. It works even better if you’ve collected enough quart size jars that you can insert the baggie into the jar and gently fold the top of the bag over the top and hold in place with a rubber band. Then sit the jar on a table or workspace. This keeps the kids from dropping the bag before they seal it.
Carefully seal the baggie with the ingredients. The trick is to push as much of the air out of the bag as possible before sealing so that the baggie won’t “pop” open during the shaking phase of the project.
Now slide this first quart sized freezer bag into the second quart sized bag. Having the ingredients double-bagged will help keep the salt and ice in the next step from leaking into the ice cream. Again make sure you get as much of the air out of the bag as you can, before sealing.
Next, take the gallon size freezer bag and put in the ice and salt. Close this bag and shake a little to make sure the salt is really covering the ice. Now open the gallon bag and put the double-quart bag of ingredients into the middle of the ice. Once again make sure you seal the bag with as little air as possible.
It’s time to have the children put on their gloves or wrap up the baggie in a small towel. They get to shake, jump up and down with the bag and even squeeze the bag a bit. Make sure they keep the ice cream mixture in the center of the ice. As the ice melts, you may need to add a little extra. If you have fairly young children, you can try a little music or a game of hokey-pokey during this process.
The stated time for shaking the bag is about five to eight minutes before the mixture freezes. Every time I’ve done this, it’s been closer to fifteen or more. At the eight minute mark mine always looks more like ice cream soup.
Educational Opportunity
If this is a school or scouting project you can use the activity to talk about the chemistry of salt and ice, the history of ice cream, or use it as a simple “cooking” project depending on the age group.