Drinking Diamonds: The Secret to Making Perfectly Clear Ice

Believe it or not, there is a science behind making ice freeze clear. If you’ve just scoffed at that first sentence, then go open your freezer and take a look at your ice cube trays. Right in the centre of the cubes there will be a cloudy white taint and perhaps a few tiny bubbles. This is caused by minerals and impurities becoming trapped in the centre as the ice freezes inward.

“The pure ice will always freeze first and the little bit left at the end is where all the impurities end up,” explains Roman Tazhdynov, co-owner at The Bibliotheca Bar & Book Exchange. Tazhdynov is adamant that he isn’t an expert on the topic but has done an impressive amount of self-directed research.

At Bibliotheca, the bar he owns with his wife Maria, crystal clear ice is served with all of their cocktails and spirits on the rocks. “Because we make it in to big cubes it melts a lot slower and keeps the drink cool for longer,” explains Tazhdynov. “It’s important to control the amount of melting for certain cocktails and with liquor served on the rocks.” The absence of small air bubbles in the cubes also decreases surface area and therefore melting time.

Tazhdynov single-handedly produces three different types of cubes, smaller ones for straight spirit with ice, larger ones for cocktails like an old fashioned, with more liquid volume, and long spears that fit in to a highball for speciality tall cocktails.

They’re cut to easily slide in to their designated glasses, leaving enough room for the perfect ratio of liquid drink to ice. The smallest pieces are reserved for spirits, helping customers to avoid taking an ice cube to the nose when tipping the glass back.

Freezing the water very slowly is key to making clear ice, but it can’t just be achieved in a typical ice cube tray. That’s because in an ice cube tray, all sides are exposed to (pretty much) equal freezing temperature as it sits in the freezer. The outside will often freeze first, but it freezes the clearest. This pesky phenomena is what sparked the most popular method for making clear ice at a hobby level.

“If you use an esky in the freezer, filled with water, and keep the lid off, the coldest part will come from the top, so it will freeze from the top down,” Tazhdynov explains. “It freezes clear right until the end, and if you catch it at the right time you can pull the block out and leave the milky white impurities unfrozen at the bottom.”

Now, however, he has moved on to a more refined technique using a small pump (designed for a fish tank) and ditching the esky. To understand this technique, think about sprinkling fish food in a tank. If the fish don’t eat it fast enough, it will eventually all end up in the one spot right by the pump on the surface. This is what happens to mineral impurities in the water as it freezes, leaving just a small cloudy corner of whiteness which Tazhdynov carves off casually with a large hacksaw.

The remaining block is sliced with that hacksaw and chiseled into appropriately sized pieces, and placed back in the freezer. “It’s such a long process that it wouldn’t be feasible to pay someone to do it. But we can do it because we’re owners,” he says, when asked why he thinks it’s not a common sight.

In future, the plan is to move production offsite and possibly supply to a few friendly neighbourhood bars. But for now, you can enjoy a brick of handmade speciality ice in one of Bibliotheca’s 120 different whiskey’s.

bibliotheca.com.au

Photography: Jonathan van der Knaap