Hot Summer. Dry Ice. (Making the Perfect Slushy with Your At-Home Dry Ice Maker)

I am a kitchen gadget snob. Not a whore, but a snob.

What’s the difference? Think back to high school. The girl (or guy) who had the reputation for being “such a whore” was the person who kissed every guy she met. The snob, on the other hand, sought kisses from only the most popular guys. For the snob, the quantity was lower but the quality was higher. Her selectivity created a demand for her kisses among the guys, which, in turn, fed her ability to be selective.

Similarly, I’m selective over my kitchen gadgets and the more selective I am, the more selective I want to be. Thus, gadgets aren’t allowed to enter my kitchen—or at least stay for long—unless they are extremely useful and/or extremely cool. (Okay, I will admit that my kitchen served as the foster home for a Yonanas Frozen Treat Maker for a short while. But that was the result of a bet (which I lost) and will be a different blog post for a different time.)

Probably the most sought after kitchen gadget for home cooks who love gastronomy is liquid nitrogen (LN2) or, rather, the liquid nitrogen Dewar.  LN2 is nitrogen that’s so cool, it exists in a liquid state. It puts almost anything it touches into a deep freeze and, thanks in part to the high end cooking shows of late, makes wanna-be Top Chefs like myself believe you can create endless unusual yet tantalizing dishes with it. LN2 is actually quite inexpensive, but storing it requires an expensive device (a Dewar), obtaining it requires a relationship with a supplier who is unlikely to deliver it to your home, and using it requires knowledge of what not to do with it, lest you hurt yourself and others. The dream, therefore, of a LN2 supply at home for my cooking is a nice one but somewhat impractical at this juncture.

So what’s a guy to do?


The Dry Ice Maker is fitted onto a 20 LB CO2 cylinder fitted with a syphon tube.

While dreaming up schemes to convince my local LN2 supplier to deliver 30 or 40 liters of the stuff to my house, I happened upon this device, which allows you to make dry ice chips on demand. Dry ice is solid Carbon Dioxide (CO2) and is sometimes referred to as the little cousin of LN2. I think that accolade is a stretch, but at only a hundred bucks and change, it seemed like a good poor-man’s alternative to the LN2 Dewar. I also happened to have a few cylinders of CO2 stored in my house because I use it to power the soda fountain in my kitchen. (I said I was a kitchen gadget snob, right?)

So about a year ago, I picked up dry ice maker and fitted it onto a CO2 cylinder fitted with a syphon tube. The first thing I decided to do was to see how quickly the dry ice could cool things down. At its extremely low temperature (less than -321 degrees Fahrenheit), LN2 can freeze things almost instantly. But dry ice is about -109.3 degrees Farenheit (3 times warmerthan LN2). So I was curious to see how quickly it could chill down a drink.

Seeing that it was the middle of the summer and I am an iced coffee fanatic, I decided to brew a pot of coffee and dump a snowball-full of dry ice into the coffee pot after I removed it from the brewer. While mixing it, I noticed four important food-related results:

  1. The coffee cooled. Certainly not as quick as if I had used LN2, but the dry ice did cool my coffee pretty quickly.
  2. The coffee did not get diluted. As it cools, regular ice turns from a liquid to a solid (water) and in turns dilutes the coffee. However, dry ice goes through a process of sublimation (turning from a solid directly to a gas) and the strength of the coffee does not change.
  3. While there was no impact to coffee strength, per se, there was an impact to mouth feel / texture. That is to say, the coffee actually became slightly carbonated. This is because as the dry ice “melts” and cools the coffee, some of the carbon dioxide actually dissolves into the coffee, essentially leaving you with coffee soda.
  4. As I added more dry ice and the coffee got colder, it started to turn into a frozen slush. In fact, when I tasted the slush it seems to be the most perfectly semi-frozen texture that’s ever hit my mouth.

So what did I learn in this experiment? Dry ice plus tasty liquid equals the best slushy you’ve ever had!

So far I’ve tried this method with two different liquids and both times the results have come out wonderful, especially on a hot day:

 



 

 

 

Stir the dry ice / Sunny D mixture until it turns into a slushy and all the dry ice has evaporated.
Pour the cold Sunny D into a cup or 2 of dry ice chips.

Recipe 1: Orange Sunny Slushy

This one’s so easy to make that even my son can do it (see pictures):

  1. Chill 2-4 cups of Sunny Delight (Sunny D to you hipsters) in the coldest part of your fridge or warmest part of your freezer. Getting the liquid as cold as possible without letting it freeze will yield the best result in the next step.
  2. Place the liquid into a mixing bowl. (If you’re using a metal bowl, you should chill the metal bowl before using it.) Add about a cup of dry ice and mix with a wire whisk. Add more dry ice as needed.As you stir, the liquid will turn to a tasty slush. Make sure as much of the dry ice as possible has evaporated before serving. There are fewer things worse than getting a mouthful of dry ice.
My son, Jamie, enjoying a Sunny D Dry Ice Sushy
The final product looking quite tasty.

Recipe 2: Mojito Slushy

A mojito is usually made with a splash of seltzer to give it some fizz. In this case, the dry ice will carbonate the mojito mixture as it freezes.

  1. Create a mint simple syrup by combining equal parts of sugar and water in a saucepan and heating it until the sugar dissolves. Then turn off the heat and add a handful of fresh mint that has been washed and bruised (or muddled). Let the mint steep for at least 30 minutes. Then strain the mixture and discard the solids.
  2. Mix the simple syrup with white/light rum, freshly squeezed lime juice and water. The exact ratios are up to you, but keep in mind that as the mixture cools your ability to taste its sweetness will get considerably less. So you want this to taste like the sweetest mojito you’ve ever made. It’s also important to note that the more alcohol you add, the harder it will be to turn the mixture into a slushy. So use the alcohol for the taste and not for the physiological effect. I generally use a ratio of about equal parts of all ingredients except for simple syrup, which I double compared to all other ingredients.
  3. Chill the mixture in a freezer. Because there is alcohol in this mixture you should be able to (and will need to) chill it below 32 degrees Fahrenheit. If you don’t chill the mixture enough, it will not properly freeze.
  4. Place the liquid into a bowl. Add about a cup of dry ice and mix it with a wire whisk. Add more dry ice as needed.

I believe you can use a similar technique with most sorbet recipes. Once you make the base sorbet mixture, chill it and mix it with dry ice for a delicious treat.

For added pizzazz, buy an Erlenmeyer flask or two when you pick up your dry ice maker and prepare your concoction tableside. I’ve done this as a palette cleansing sorbet course for a few dinner parties I’ve thrown and the guests are always stunned.

Author’s Notes:

  1. Still want a way to get LN2 at home? Then read Dave Arnold’s Liquid Nitrogen Primer
  2. Getting (and storing) CO2 is much easier than LN2. CO2 can be obtained from any welding supply store. If you’re using it for dry ice, you need to get a CO2 cylinder fitted with a syphon tube. If you’re using it for other purposes, such as carbonating liquids, you can use a standard CO2 cylinder. The cylinders come in different sizes by weight (5 lb, 20 lb, 50 lb. etc.) and are fairly cheap to refill. You can also store them almost indefinitely whereas LN2 evaporates quickly if gone unused.
  3. Using a CO2 cylinder to carbonate liquids is way more economical than using a Soda Stream or other soda-making device. Using straight CO2 or dry ice is also way cheaper to use than ISI CO2 cartridges to carbonate fruit, a technique that was popularized several years ago by Homaro Cantu. (If you’re thinking about getting a CO2 cylinder  or commercial soda equipment for home use, send me an email or leave a comment. I’ve done a ton of research over the years about where to get what you need and how to create the perfect at-home setup.)