A confession: I have always been fascinated by ice. Especially clear ice has impressed me for as long as I can remember. The way it breaks the light is so beautiful. The shapes getting created by nature are amazing, be it in glaciers or just icicles. And maybe the greatest thing about this is the clarity which these natural ice sculptures have.
Long lasting ice and the bubbles of thaw
When you get into cocktails and the art of making drinks you will eventually come across ice. Be it in a shaker or in a great spirit just served on the rocks. Videos of Japanese bartenders meticulously chiseling a perfectly round ice ball from a chunk of ice that looks like a brick of glass made me crave for perfect ice at home even more.
Now the great thing (beside the looks) about these ice balls is the fact that they melt really slow. In some drinks you want exactly that. It does not make sense to enjoy a wonderful spirit and discover that it has been watered down to a boring, diluted something after 2 minutes. The bigger the ice is by volume and the smaller the surface area is compared to this volume the better. So what we want are big ice objects, be it cubes, or ideally spheres, depending on the drink and glass.
But when we freeze water in our freezers we never get that kind of ice. It is usually clouded and the smaller the ice cubes the worse the clouding. So what can we do about that?
Reasons for ice clouding
Small ice cubes are pretty much all cloudy, bigger ones (I have 5 ˣ 5 ˣ 5 cm silicone molds for instance) could be 50% clouded. Some sources say you should boil the water at least twice before making ice to take out the small bubbles which you can notice when leaving a glass of water sitting over night. Distilled water is what others recommend. While many of these things have more or less had influence on my ice cube trials none of the above advices have proven to be a real solution to the problem.
A working solution for making crystal clear ice at home
So, after a while, years in fact, of trial and error, hanging out in physics forums etc. I came across a more practical solution some time ago. And guess whatL This one actually works well enough and brings you the clear ice of champions. Let me share the process with you.
Step 1: Plan ahead, 24 hours in fact
The first and foremost thing you need is time. Clear ice takes time. So no rushed 2 hours before the guest arrive and then continually checking whether the ice is ready every 5 minutes. Your times may vary depending on your setup but I have a pretty precise 23.5 hours duration figured out for my setup.
Step 2: The setup for crystal clear ice
- You need a large freezer space, level and accessible so you can get the water in without problems.
- I have a styrofoam box (the insulator box) which I have customised to exactly fit into one of our freezer drawers.
- Inside the styrofoam box goes a plastic container for the water. This must fit inside the insulator box leaving no air between the two. This is important! The styrofoam is supposed to insulate the inner container from the cold inside the freezer. We want the water container to be insulated from the bottom and the sides and only the top open and exposed to the freezing cold air inside the freezer.
- It is hard to find a matching set of insulation and water containers to be honest but with a bit of research you'll find something. I filled a small gap with a bit more styrofoam which I had to cut off the top for instance.
Step 3: Preparation
If you feel like boiling the water feel free to do that. Twice is nice as well. If you have water where you live that leaves you with limescale residue faster than you can say 1, 2, 3 it is worth considering getting a filter or maybe some bottled water.
Now, once the water is ready get it into the container and insert that container into the insulation box. On top you could cover the water with aluminium foil or any other thin protection. A lid might be too much already. This is only to keep smells and odours from the freezer to get into our ice. Now, the whole thing goes into the freezer and we need to wait.
Step 4: Getting the half-frozen ice container out
Here comes the important part: If you leave this in the freezer for a week or even 3 days you will get a block of ice with clouding on the bottom half maybe even two thirds up.
When our water freezes it starts from the top. A thin layer of ice forms and another layer underneath. Bubbles are basically pushed down by the ice. This works fine as long as the ice is coming from the top. At some point the water is too cold and freezes not just from the top. Thats when the air gets trapped in small bubbles and that's the clouding.
So we need to be alert to see when this starts to happen. It makes sense to try how long it takes for your setup to reach that tipping point. Just check on it after 12 hours and then regularly. When the first bubbles get trapped get it out of the cold.
Step 5: Get the water out (and your chainsaw ready)
Now you get the water/ice container out of it's insulation box and let the remaining unfrozen water rinse away. I usually need to punch a small hole into the ice block since it is like a water cushion inside.
After that I chisel off the ugly thin bits with a few hits with a knife. now you have an awesome and clear block of ice.
Cutting this ice is easy. A bread knife is my weapon of choice. But fear not, you do not have to saw like a maniac, unless you want to keep your chainsaw skills trained and sharp. Carving a line is enough. After that I leave the knife right there and hit it from the top once with a heavy kitchen utility. This usually makes the ice crack in a super neat fracture. Done.
Step 6: Cut cubes and store away
I usually create cubes fitting the typical glasses and store them in a sealed freezer box. This goes back into the freezer. Again this is to protect the ice from drawing odours when inside the freezer.
You must be nuts! So much work for a bit of ice?! If you have read so far I am actually convinced that you might try it anyway. There is something about clear ice that made you read this far which makes you a clear candidate for trying it. Sometimes I am too lazy as well or I have too little freezer space or time. But when I get the ice prepared people always notice it and ask about the ice. My Instagram shots with clear ice have always performed well and again the clear ice was the topic of discussions as well.
Hopefully this helps you in creating your perfect ice cubes. It is the simplest way if you have no access to buying clear, large ice cubes.