Spirit Stones

Usage

Chilling whisky, rum or brandy a few degrees when you want no water in it at all. Three or four stones in a 50ml pour. Never in a cocktail, where dilution is part of the recipe rather than a fault.

Why They Underperform

Ice does not chill a drink mainly by being cold. It chills it by melting.

Changing a gram of ice from solid to liquid absorbs about 334 joules, the latent heat of fusion, and that is where almost all of the cooling comes from. Simply warming a cold solid absorbs a small fraction of that: soapstone has a specific heat capacity around 0.98 J/g·K, so warming a stone from −18°C to 10°C absorbs perhaps a thirtieth of what an equivalent mass of melting ice does.

The result is measurable and modest. Four frozen stones drop a 50ml whisky by two or three degrees and then stop. Ice takes the same pour to near-freezing and holds it there.

Against Ice

Ice wins on cooling by an enormous margin, and loses on the one thing the stones exist for: it adds water.

Whether that matters depends entirely on the drink. A cask-strength whisky at 58% is usually improved by a little water, which breaks the surface tension and releases aromatics the alcohol was holding down. A 40% blend that has already been reduced at the distillery gains much less.

So the honest position is that stones solve a real but narrow problem: you want a spirit a few degrees cooler and genuinely undiluted. If you want it cold, use ice, and preferably one large clear cube, which dilutes slowly.

Soapstone or Steel

Soapstone is the traditional material: non-porous, soft enough not to scratch, and with a slightly higher heat capacity than steel, so marginally better at the job.

Stainless steel stones are usually hollow and filled with a gel that freezes, which raises their capacity a little and makes them the better performer of the two. They are also easier to clean and will not chip.

Both will scratch glass if dropped from a height into a heavy tumbler, and steel more readily than soapstone. Tilt the glass and slide them down the side rather than dropping them in, which is worth doing regardless of material.

Freezing and Keeping

Four hours minimum, and overnight is better, since they are dense and take longer to reach freezer temperature than their size suggests.

Wash and dry them completely before they go in the freezer. Soapstone in particular picks up freezer odours if stored damp, and a stone that tastes of frost will put that straight into a 50ml pour of something expensive.

Keep them in a sealed container or a zip bag rather than loose on a shelf, and wash them again after use, since spirit residue dries on and builds up. They last indefinitely, which is fortunate, since most sets get used twice.

What to Look For

• Sealed food-grade stainless rather than bare soapstone, for washability
• Larger cubes: more mass, more chill, less clutter
• A freezer tray or tin included
• Rounded edges that will not scratch a good glass

Professional Tips

• Freeze for at least four hours, longer if you can.
• Three or four per glass. One does nothing.
• Lower them in. Dropped stones chip a glass.
• Wash and dry fully before freezing, or they taste of freezer.

Specifications