Clear Ice Mould

Usage

Producing large cubes or spheres for spirits served over ice and short drinks: Old Fashioned, Negroni, whisky on the rocks. Anything where the ice sits in the glass for twenty minutes and its melt rate decides how the drink finishes.

Directional Freezing

Water freezes from the outside in, and as it does it pushes dissolved air and minerals ahead of the ice front. In an ordinary tray those impurities end up trapped in the middle, which is the white cloud you see.

A clear ice mould insulates every face except the top, so freezing happens in one direction only, downward. The air and minerals are driven steadily into the bottom of the mould, into a reservoir designed to be thrown away.

The result is a block frozen from clean water outward, with the impurities removed from it rather than distributed through it. It is the same principle a commercial Clinebell machine uses, scaled to a cupboard.

Why Clear Melts Slower

The cloud is thousands of trapped micro-bubbles, and each one is a fault line.

Air pockets increase the internal surface area enormously and create stress points where the ice fractures. Cloudy ice cracks when it meets a warm spirit, and each crack exposes new surface, so it melts faster and dilutes the drink quicker. It is also why cloudy ice makes that loud snapping sound in a glass.

Clear ice is a dense, near-uniform solid. It melts from the outside at a steady rate, holds together, and gives a short drink a far longer usable life. In an Old Fashioned that is the difference between the last sip being a drink and being water.

Why Yours Is Still Cloudy

Three usual causes, in order of likelihood.

The freezer is too cold. At −18°C the water freezes fast enough that the ice front outruns the impurities and traps them anyway. Around −8°C gives the slow, directional freeze the mould needs, which is why many moulds recommend turning the freezer up or using a warmer shelf.

You froze it too long, so the sacrificial base froze solid and pushed cloudiness back up. And the water was not the problem. Boiling or filtering helps marginally, but directional freezing is doing almost all of the work regardless of what you fill it with.

Cubes or Spheres

Cubes, on the physics. A sphere has the smallest surface area for its volume, which sounds ideal and matters less than people assume.

A large cube is easier to make well, sits stably in a glass, and stacks in a freezer. A sphere looks better and rolls, which in a heavy rocks glass is a genuine minor irritation. The melt-rate difference between a 5cm cube and a 6cm sphere is small enough to be lost against how cold your freezer runs.

Buy whichever you will actually use. The gain over ordinary tray ice is large; the gain of one shape over the other is not.

What to Look For

• A genuinely insulated case for directional freezing, not just a silicone shape.
• A design that leaves a trimmable cloudy base.
• A size that fits your glassware.
• Food-grade silicone that releases the ice cleanly.

Professional Tips

• Use it in a freezer at around −8°C rather than −18°C if you can.
• The cloudy base is meant to be thrown away. That is the design.
• Cut and shape with a serrated knife, not a chisel, unless practised.
• Let a cube temper a minute before use or it can crack the glass.

Specifications