Dry Ice Solidification and Carbonation

We ran out of ice cream at my house, and I wanted to eat some yesterday, so I went ahead and made it myself. I didn’t know of anywhere to get liquid nitrogen on short notice, so I just decided to use dry ice (which is solid carbon dioxide) as a substitute. Since there is an age requirement to buy it, my dad bought me a 10 pound chunk from the grocery store, which was much more than enough to make the three quarts of ice cream that I had planned for.

I started by making the bases for my coffee and my vanilla ice creams the day before because I wanted to give the flavors ample time to develop. I started with 3 cups of heavy cream, heating it up on the stove before adding 3/4 cup of sugar and a cup of coffee beans:

I also used up all of the cinnamon…

For the vanilla ice cream, I followed a similar process, only adding vanilla extract in place of coffee beans:

Fun, fun, fun, fun, looking forward to the weekend.

I refrigerated the bases overnight, straining out the coffee beans in the morning because it was starting to get a little bitter. Surprisingly, the color of the coffee base barely changed, just becoming slightly darker and browner than it was to start with.

The next day, I made my berry sorbet base, blending a lot of berries with a little bit of water. I then strained it to remove the seeds from the mix:

All you Twihards out there can pretend it’s blood.

Finally, it was time to work with the dry ice! I don’t have a stand mixer, so I used a whisk and a large wooden spoon stir the dry ice into the bases. There was evaporated carbon dioxide everywhere while I did this, so much so that I didn’t really have the opportunity to take pictures. Here’s one that I managed to get:

This part took much longer than I expected and was much more tricky to pull off correctly. I was unable to crush all of the dry ice into powder, so there were a lot of frozen chunks in the ice cream that eventually evaporated. However, if I plan to do this for the Bite of IS in a few weeks, I need to figure out how to do this quickly and without chunks.

In my opinion, the sorbet came out much better than the ice creams. I ended up whipping a lot of air into the ice cream bases so they turned out a little bit like whipped cream, at least texturally. When I put them in the freezer, they have more the consistency of really soft ice cream, which is good. The sorbet was just perfect: smooth, mostly flavored by the berries (not sugar), and very few chunks.

I think I’ll do emulsifications with soy lethicin next. That seems fun and exciting.