This was really, really fun.
As part of the class “Kitchen Science” we made delicious ice cream using compressed CO2. No icy, home-made tasting product. No ice cream mixer. And because, like myself, the kitchen science crew has zero patience, no waiting.
It was crazy easy to make too. There are three things that you pretty much need to do it though:
- Stand Mixer
- Food processor or a good blender
- Food-grade dry ice
The last item on that list might be easier to get than you think, especially if, like Parts and Crafts, you’re in close proximity to Cambridge, MA. We source our dry ice from Acme Dry Ice and buy a small box of their pellets for around $14. We ended up making two batches of ice cream, using the recipe below, but had a bunch of dry ice left over. In the future I plan on making four batches (2 quarts of heavy cream) to use up all the dry ice.
Dry ice note: There’s food-grade and non-food-grade dry ice out there. Because we’re adding dry ice directly into the ice cream, we really don’t want any contaminants or lubricants from the machinery that compresses the dry ice in our food. I would call and ask your supplier if it’s food grade or not.
How we did it:
- Prep ice cream base. We just did plain ol’ vanilla and chocolate, but anything works: sorbet, sherbet, custard. The recipe that we used was a variation on all the recipes that we saw online and in our cookbooks. We added all the ingredients to a small saucepan and heated until everything was dissolved and looking good.
- 2 cups heavy cream
- 1 cup whole milk
- 1/2 cup sugar
- 1/4 cup corn syrup
- 1 Tbs vanilla extract
- For the chocolate ice cream: baking cocoa (although we just threw in a bunch of dark chocolate)
- Grind the dry ice to dust! Dust! Put about 2 cups in a food processor and hit go. Took us about 20 seconds in the Cuisinart.
- Add ice cream base to the mixer, crank it up to medium speed, and slowly add dry ice dust until it looks like ice cream. We made sure that all the dry ice was sublimated before adding more and that all the dry ice was gone before we ate it. And no, you should never eat dry ice! But a small, dust-sized particle remaining will not harm you, just taste like pop-rocks on your tongue.
- Eat! We left it in the freezer for about 10 minutes before scooping, but it tasted great right off the paddle too.
A note on emulsifiers:
We added a pinch of guar gum to half our batches to taste test the results. The proper proportion should be about 0.5% , but we didn’t have a gram scale at the time to make sure. Guar gum acts as a emulsifier and stabilizer in ice cream and also helps prevent the formation of large ice crystals that make ice cream grainy and freezer-burny. I’m not sure we could really taste any difference in the amounts that we added, but when we added a lot (like a tablespoon) of guar to a cup of milk, we made this: