In 2024, Christoph Salzmann, professor of physical and materials chemistry at University College London, discovered a new form of ice that more closely resembles liquid water than any other known ices. UCL calls him “Iceman.” He knows his frozen H₂O. “Having been mined from a glacier adds to the price tag—but we can make purer ice in the lab than you would ever be able to harvest from a glacier,” Salzmann says.

Glacial ice starts as snow. When it falls and compacts, it has many grain boundaries, and it's these that make the ice look white. Over thousands of years, pressure forces the ice into much larger crystals with fewer grain boundaries, so it appears clearer. The clear ice in your drink is, in fact, one large single crystal. “But even in glacial ice you would still find tiny gas inclusions,” says Salzmann. “This is something we can entirely avoid in the lab.”

By freezing water slowly, layer by layer from just the bottom up, known as directional freezing (not possible with an ice mold in your standard freezer because the cold air comes from all directions), ice will grow in that orientation, and, as it grows, it will push out all the impurities. Salzmann and his team have even created a machine using this principle that makes perfectly clear ice.

“We got a trunk freezer where you open it from the top, then we put a big hole in the lid—which I don't recommend people do,” Salzmann says. “Then if you lower a tube of pure water into your freezer unit very, very slowly, then you would be making high-purity ice.” Salzmann's sophisticated apparatus lowers the large tube of pure water by just millimeters per day, ensuring a slow, bubble-free, clear freeze as the impurities are forced upward away from the forming ice.

The drinks industry uses the famous-in-the-trade Clinebell machines, which operate on the same principle. The original Clinebell machine was invented in 1983 by Virgil Clinebell after he saw how ice freezing on top of rivers and streams was clear. It's likely no exaggeration to say that without Clinebell, the premium ice sector as it exists today probably wouldn't have happened. The Colorado company now sells its machines all over the world, each making single blocks between 25 and 300 pounds that are then cut up.

Neither Salzmann's lab-grown gear nor Clinebell's contraptions are any good for the likes of us, though. What we need is a more home-friendly solution. Fortunately, Salzmann has one.

“Take a polystyrene box, something thermally insulating, then pour the liquid water in. Now, because the polystyrene is thermally insulating, the water will only get coldest at the top, and then you replicate this directional freezing,” he says. “You still have the problem that it will freeze from the top downward, so you'd be left with the impurities at the bottom.” So you either remove the clear ice before it freezes fully to the bottom of the container, or wait till it's all frozen, then cut off the cloudy bottom section of the block, leaving the clear ice above. You can get special ice knives for doing just this.

Camper English recommends the same method using a hard-sided picnic cooler with the cooler's top off. The water will only freeze from the top down, and only the last quarter of the ice block will be cloudy.

Salzmann explains that one of the many special properties of ice is that it actually gets softer toward its melting point. “So when you take ice out of the freezer at min18 degrees Celsius, it's much more brittle compared to if we let it warm up a bit to -1 or -2 degrees. So, if you're carving, it's definitely a good idea to leave it for a bit. Then it becomes nicer to work with,” he says.

If you don't want to bother with cutting your own cubes, then Klaris has you covered. Klaris has labored to make a kitchen countertop version of the classic Clinebell machine, and we loved it. Trouble is, it costs a hard-to-swallow $550. Now, however, the company has created a new, cheaper version called the Klaris Mini, which retails at a much more palatable $300. The small 8 x 8 x 8-inch box produces two ultra-clear, 2-inch cubes at a time, which can then be stored away in your freezer if you're stocking up before a party.

Nice Ice

Now, these methods effectively banish those pesky bubbles, but what about replicating that glacial purity in your homegrown luxury ice? It turns out there are three solutions here, and all are easily attainable at home—the last one remarkably so.

“Glacial ice is quite pure because it comes from rainwater,” Salzmann says, adding that the way to get cleaner water at home is to remove the ionic impurities (dissolved inorganic salts, minerals, and metals that carry a positive or negative charge, such as calcium, sodium, chloride, and sulfates). Salzmann says a water filter will remove much of the tap water impurities and pollutants, or you can use what Salzmann recommends: deionized water—"the kind you would use for doing the ironing.”

But we're not done yet. Now you have to get rid of the gases in your water that will increase the chances of cloudy ice. To do this, boil your water first to force out any gas, then freeze it before it can reabsorb any more.

There's a nasty problem with drinking too much very pure water. “Within your cells in your body, there's a lot of water—but there's also lots of other stuff, dissolved materials that exert osmotic pressure on your cell membranes,” Salzmann says. “If the medium surrounding your cells does not have the same content of dissolved materials, there's a different osmotic pressure. So, the bottom line is, if you drink too much deionized or super-pure water, it would be quite bad for you.” Now, we should point out here that you'd have to drink an awful lot of this pure water to run into trouble—a few ice cubes won't come anywhere near close to causing you any problems.

Still, we can swerve even this last potential pitfall by turning to the sage advice of Kevin Clinebell, grandson of Virgil, who now runs the family company with his brother Scott.

“I've got a customer in Las Vegas that studied [using water filters], because Las Vegas has very poor water," Clinebell says. "Their dissolved solids are something to the tune of 450 parts per million, whereas here [in Colorado], it's 45 to 48 parts per million,” adding that the system was also very inefficient. “So he started playing with different bottled waters—Fiji, Aquafina, all different types. The one that he found that was as close to perfect as you could get is Crystal Geyser bottled water. That one gave him the best results of any water that he's ever tried, and he's running reverse osmosis and everything else.”

So there you have it: the definitive answer. Crystal Geyser bottled water—boil it, freeze it straight away in a polystyrene container or cooler with the lid off, then cut it only after it's thawed to near melting point. You'll have the best luxury ice money can buy—ice to rival 100,000-year-old Greenland glaciers sold for a comparative fortune in the world's most exclusive bars and hotels—for practically no cost at all. You're welcome. Mine's a Negroni.