Hand Carving Ice Cubes 🥃
a general guide for freezing water
I really enjoy whiskey and making cocktails, and that hobby has now expanded to include carving my own ice cubes. It’s mostly for aesthetic and enjoyment. I admit that getting really excited about large blocks of frozen water is ridiculous, but I do. Below are some notes and observations about things I’ve learned as I’ve improved my process. If you’re interested in carving your own cubes, I hope you find this helpful. Cheers. 🥃
So, there’s several parts to this question, and I’ll try to answer these somewhat concisely.
Why Large Cubes?
The first reason is that large ice cubes melt more slowly than smaller ones because they have more surface area. These are not ideal for drinks you want to rapidly chill, such as gin & tonics or Moscow mules. They’re more suited to whiskey and whiskey cocktails, drinks you want chilled but not over-diluted. You could chill the whiskey and/or the glass, which is fine until your hand warms up the glass. You could also use whiskey stones, which sound like a good idea, but I’ve never had them work as well as I’d like. If I want whiskey undiluted, I drink it neat, and if I want it chilled, I make these cubes.
Why Not Use An Ice Mold?
Ice molds are fun, and you can get them in all kinds of shapes. I was using them for a while, and they work really well for creating large cubes or spheres quickly. But they always came out so cloudy, even after purifying the water. They functioned fine, but they didn’t have the aesthetic I wanted. While talking to a local bartender a while back, I asked him how they made their cubes so clear. He said that the only way to get really clear ice is to carve it yourself. In my experience he’s been absolutely correct. There’s probably a way to create a mold that could do it, but I’ve found carving to be the best route for me.
Why Do You Care If Your Ice Is Clear?
It’s mostly aesthetic, but how food and drinks are presented matters. You may make a decent Old Fashioned, but you’re more likely to enjoy it if it looks appealing. Some people claim that clear ice is more dense and pure and therefore melts more slowly and consistently. I haven’t validated those claims, and I assume that while there may be some truth it, it’s mostly nonsense and snobbery. I do it because I like carving the cubes, and I like how it looks.
This is an involved process that takes a couple days minimum to get a set of cubes. That said, if you make them a batch at a time, you can get 10–12 cubes at once, and they preserve well in the freezer. So you can pretty easily stay ahead of it (as long as you’re not drinking six cocktails a night). But before you read too far into this, it might be helpful to know some of tools ahead of time.
- insulated cooler (6"x 9" or larger)
- tape measure
- flat (not ribbed) griddle
- serrated knife
- chef’s knife (preferably sharp and one you don’t care about)
- wooden (or rubber) mallet
- large square (or ruler)
- wooden (or rubber) cutting board
- wax paper
- 9"x13" Pyrex pan (or something similar)
- Shaping & Carving
There are two things main that make ice cloudy: impurities and multi-directional freezing. The first step is to remove impurities. You could probably start with purified water, but I’ve always boiled mine before freezing. In Colorado, most of our water was recently snow, so it’s pretty clean to start.
I use a 6"x9" cooler. It’s nothing fancy, but it’s what we had that fits well in our freezer. I can make about 12 cubes that are roughly 2"x2"x2". We’ll talk more about size later, but all this to say I usually fill the cooler up anywhere from 2.75–3" full of water. I use a small tape measure to gauge the depth. Keep in mind that you’ll lose a little of this in the boiling process, but the ice will expand as it freezes. Filling it up that much gives you some wiggle room. You could fill it up more, but I haven’t found an advantage to doing that, and the cubes end up being a bit too large for your glass.
Transfer the water to a large pot and bring it to a boil. I usually let it boil for about five minutes, but I haven’t played with different amounts of time very much. I want to make sure the water is pure, but I don’t want to lose too much to evaporation. So, like most things in this process, it’s a balancing act.
Once you’ve purified your water, pour it back into the cooler. My cooler is soft with a hard-shell removable liner which is super helpful for getting the block out later. I usually measure the water depth again to see how much I lost to evaporation. I usually end up around the 2.75"-2.5" range, which is great.
The insulated walls of the cooler are absolutely key to getting clear cubes. Because the ice is insulated on every side except the top, the water freezes in one direction from top to bottom. This is also why it’s essential to leave the top open during freezing. We want to encourage the ice to freeze that way as much as possible. If the ice freezes in multiple directions you’ll get odd crystal structures and trapped air pockets, all of which lead to cloudiness.
Because the water is only freezing in one direction, it’s going to take a lot longer to set. With our freezer set at -1°F (about -18.33 °C), the 6"x9"x3" block usually takes about 18–24 hours to completely freeze. If you have a larger cooler, it’ll take longer, and it’s definitely not something you want to chance and pull out too soon. Starting over is the worst.
It’s also important to put the cooler in a place where it will be undisturbed in your freezer. If it moves much before it sets, you’re risking lots of air pockets getting trapped inside.
Shaping & Carving
Once your ice is set you can gently remove it from the cooler and onto a cutting board. I use a large wooden cutting block, but you could use rubber or something soft. You don’t want to put the ice on granite or another hard surface, because the ice will take all the impact and shatter. I usually inspect the block to see how it froze. It should look a little cloudy on the outside because the ice is dry, but you should be able to see through it somewhat.
The block has expanded a bit as it froze, and likely isn’t in a perfectly rectangular shape. You may also see a lot of air pockets at the bottom of the block, and that’s totally fine. In the shaping process, we’ll remove those air pockets and get the block in a more rectangular form.
I use a large, smooth iron griddle for shaping. It’s nice because I can easily fit the whole block on the griddle and not have high walls on the edge of the pan. I make sure the griddle is heated evenly and then turn the gas down to low. If the griddle is too hot, you can fracture the ice, which isn’t the end of the world, but also isn’t ideal.
Once the griddle is at a good temperature, place the block on each edge until it’s in a uniform shape and you’ve removed all the air pockets. You’ll want to remove the block from heat several times to get rid of the excess water. This is all a balancing act. You want the block to be clear and a uniform shape, but you don’t want to melt too much ice. This is part of the reason why I start with ~3" of water before freezing. It gives me some wiggle room to shape the block.
NOTE: You can wait to remove some of the air pockets after you carve the cubes, but I found doing this first results in less melting. But try it out, and see what works best for you.
Okay, on to the main show. Carving ice is a lot easier as it warms up. That’s another benefit of shaping the ice on the griddle first, but again, this is balancing act. You’re going to want to move quickly on this part, which takes practice. Once you have you block in the shape you want, move it back onto your cutting board. I use a large, metal square to measure the block. It also helps keep the ice from sliding off the board.
I first measure the block and roughly score it horizontally about every 2.25" with a serrated steak knife. You don’t need to score it deeply. Ice wants to break in a straight line. scoring gives it a starting point. You’ll then place your chef’s knife on the score and tap it with a wooden or rubber mallet. A softer mallet helps prevent the ice from fracturing, and it’s easier on your knife. That said, you should use a sharp, but cheap knife for this.
Once you’ve separated the block horizontally, score them vertically and repeat the process to make your cubes. You may notice that the ice is warm enough at the this point to cut with the serrated knife alone.
Once the cubes are cut, you’ll want to freeze them really fast. But before you can store them, you need to refreeze them. Place some wax paper (not parchment paper) inside a large pan. I use a 9"x13" pyrex dish, but it doesn’t really matter. You want a pan large enough to keep the cubes from touching one another. The wax paper keeps the cubes from freezing to the pan. Quickly dry off each cube to remove the excess water and place on the wax paper. Then transfer the dish to the freezer and wait about 30 minutes.
Once the cubes are frozen again, you can transfer them to a bowl or another container in your freezer. They can touch, and you won’t need to worry about them freezing together. The cubes keep pretty well in the freezer, and they don’t lose much of their size.
Thanks for reading! I hope this was helpful! This is a bit of a departure for me. I normally write about design and software development. You can find me on Twitter and GitHub, and you can also subscribe to my newsletter!
Please enjoy responsibly. 😀🥃