The Science Behind Those Fancy Clear Cocktail Ice Cubes

If you've ever visited a high-end cocktail bar, you might have noticed they aren't just using any old ice. Using the right type of ice is an easy way to elevate certain cocktails. Some might fare well with rough pebble ice; others will do better with larger ice cubes or spheres that will dilute your drink more slowly. In the latter case, a next-level upgrade is to use clear ice instead of the more common opaque kind.

Most ice turns cloudy as it goes from transparent water into solid ice because of impurities. These can include particulate matter and even simple gases, such as oxygen, that get trapped inside as the ice freezes. They serve as magnets for the formation of larger ice crystals, which give the interior of ice cubes a frosted look. It's not difficult to make ice cubes without these impurities, though; it can even be done at home without specialized equipment.

Using clear ice won't change the flavor of your cocktail, but aesthetics matter — it's said that we eat (and drink) with our eyes first. To show off the golden mahogany tones of an old-fashioned or the ruby red of a negroni, you don't want your ice muddying things up.

If you want the easiest method of producing clear ice cubes at home and don't mind paying for it, all you have to do is buy a clear ice tray. Manufacturers such as Dexas sell ice cube trays that take advantage of the freezing process to concentrate impurities in a separate part of the tray. That way, you're left with beautiful, clear cubes.

If you don't want to buy specialized equipment, you can also follow YouTube channel Cocktail Chemistry's method. It uses a cooler with the lid removed to produce blocks of clear ice that can then be carved down into smaller cubes or ice logs that fit into highball glasses.

The way it works is surprisingly simple chemistry. The walls of the cooler are insulated so that the ice freezes from the top down. The impurities are the last thing to freeze, so they settle at the bottom. Before the entire block finishes freezing it is removed, and the clear ice is separated from the rest of the half-formed ice. It's truly genius and will let you batch clear ice cubes to have ready for your next entertaining opportunity.

Clear ice cubes aren't just for alcoholic drinks. They can also add a subtle flair to a glass of lemonade; you can even make them flashier, if you want. It's possible to use regular ice to freeze berries or edible flowers inside, but the beautiful colors of these treats will show even better through clear ice cubes.

Be sure to use fruits and berries that don't float so that they'll be completely submerged in your ice cubes. (If you're following Cocktail Chemistry's methodology, you might need a plastic rack or shelf to support the fruit in the clear section of the ice.)

Freezing edible flowers, meanwhile, is slightly more difficult because they float. To make sure that they're freezing in the center of the cubes, you'll have to freeze them in sections, which will allow them to partially freeze. Adding more water will fill the rest of your tray's mold with ice and trap the edible flower inside.