3 Ways to Make a Cuba Libre Slushie

When temperatures began approaching 100 degrees recently, I flashed back to childhood summers when my sisters and I would cool off by making homemade slushies with off-brand cola and cheap plastic slush mugs. It was an exercise in planning and patience: the canisters had to be frozen overnight and once the cola was poured in, one had to scrape and stir continuously until the texture was just right. But we had nothing else to do, and the payoff was a perfect icy cola treat.

It occurred to me that I was once again facing long days at home with more time than resources on my hands. Our current ice cream maker, it seemed to me, was basically a mechanized slush mug, and I wondered why I couldnʻt use it to make slushies again--perhaps, now that I am an adult living with other adults, one with a splash of rum added, i.e., a Cuba Libre. I had to try.

A Cuba Libre has three ingredients:

• cola (Mexican coke is preferred for its taste, but feel free to use the cola of your choice)
• light rum
• lime

A cutting board, knife and citrus juicer for the lime; and a measuring cup and bottle opener if you need it are helpful tools. Chilling ingredients speeds the process. The timing of the following methods is based on refrigerated rum and coke.

To a 12 oz. glass bottle of Coke, I added 3 oz. light rum and the juice of 1/2 to 3/4 lime, saving a wedge for garnish. This is the blend that will be used in all the following methods of freezing.

Of course, this can be made non-alcoholic by omitting the rum. The lime is also not necessary--our childhood slushies were made with nothing but cola, and we still loved them. So feel free to adjust this formula to your taste.

Note: the International Bartenders Association lists the proportions of a Cuba Libre at 50ml rum to 120ml coke. For a 12 oz. bottle, this would mean adding 5 oz. of rum, or over a half cup. I opted to go lighter on the rum, both because more alcohol changes the freezing point and because I prefer the taste. Frozen drinks tend to taste weaker than liquid ones, so having more cola flavor in the blend to start with ensures a nicer-tasting frozen concoction.

As noted earlier, my ice cream maker works just like a slush mug: you freeze the canister overnight, pour in your blend, and turn it on. The only difference is that the machine does the stirring for you.

Time required: 15-20 minutes

What if you donʻt have an ice cream maker? Enter Method 2, which consists of simply freezing the blend in a loaf pan or whatever fits in your freezer.

Depending on your freezer, it may take 3 hours or more to get to a soft slush that can be stirred and broken up with a fork. If you refreeze it, the chunks will remain broken up as they get colder. This is essentially making a Cuba Libre granita.

Alternately, you can freeze the block overnight or until solid and break up the chunks in a blender turned on the lowest speed. Be careful not to overblend here--you donʻt want to break the ice down into liquid again.

Time required: 3 hours +

Then again, you may not even have a freezer to use. You may be traveling, or live in a room-sharing situation with limited freezer space. Or your freezer may be small and/or already full. Enter Method 3, an old camping hack for making ice cream.

For this, you will need two different sized ziplock-style bags: quart and gallon. If you have a choice, the freezer ziplocs are sturdier and will hold up to the ice and shaking better. Pour your blend into the quart bag and seal it tightly, eliminating most of the air but giving it space to expand. Put this quart bag into the gallon bag and fill the gallon bag with ice, sprinkling liberally with the rock salt. The rock salt will lower the freezing temperature of the ice, drawing on the heat of your blend as it does so, and thus chilling it faster than ice alone would. We usually use two gallon bags, one inside the other. This contains and leaking and hopefully also adds a tiny extra layer of insulation. Once you have your blend inside the bag inside the (bigger) bag(s), all you do is shake. I recommend an oven mitt to keep your hands from freezing, and some music to keep it lively.

Time required: 15-20 minutes of vigorous shaking

Like TikTokkers who freeze and shake their bottled milky Frappuccinos to get the texture of an in-store frap, you can also freeze your coke in the bottle, as shown in this video. This method is not recommended for the glass bottles that Mexican Coke come in since they could break in the freezer, but it was too intriguing not to try.

The plastic bottles hold 500ml of liquid, so first pour out about 1/2 cup of coke from the bottle and replace it with an equal amount of rum and lime juice. Screw the lid back on and place in the freezer for 3-4 hours. It is ready when you start to see some freezing around the edge of the bottle. At this point you can simply tap the end of the bottle hard and it will accelerate the crystallization process. Pour it into your cup and if you need to, drop a piece of ice in the center, and/or give it a stir. I was never able to get the ice to freeze as solidly as with the other methods, but it still makes a really delicious slushy drink.

Time required: 3-4 hours (use a timer--you donʻt want to go too long and freeze the mixture solid)