What size ice for a cocktail shaker?

There is no single right cube, but the useful ranges are narrow. The table is what to reach for.

On quantity: fill the large tin about three-quarters. You want ice above the liquid line, because the cubes need room to travel - a shake is the ice moving through the drink, not the drink sloshing around some ice.

Shaking is heat exchange plus controlled dilution. Both happen at the surface of the ice, so surface area sets the speed. Small cubes have a lot of surface area per unit of mass, which sounds good until you notice what else it means: they melt fast, and melting is dilution.

Two cubes of the same mass behave completely differently depending on their condition. A dense, dry, properly frozen cube at around minus 18C has cold capacity below the freezing point - it has to warm up before it starts melting at all, so it chills before it waters. A wet cube sitting at 0C with a film of water on it has no such buffer. It dilutes from the first second.

• Too small: disintegrates in four seconds, over-dilutes, leaves shards that slip past the strainer.
• Too large: not enough surface area to chill in a ten-second shake, so the drink is under-chilled and under-diluted.
• Too wet: no temperature buffer, so melting starts immediately. This is the one that ruins most home drinks.
• Too few: the tin warms up, the ice vanishes and you get a watery drink that was never actually cold.

That last point is why ice is the first upgrade we recommend on this site, ahead of almost any tool. Best ice for whiskey covers the glass side of the same question, and directional freezing explained covers why dense ice is a mechanism rather than a brand.

1. Freeze a day ahead, not an hour. Ice needs time to equalise down to freezer temperature. Fresh ice is wet ice.
2. Keep it in a lidded container, not the tray. Open trays sublimate and pick up freezer smells, and the surfaces glaze wet every time the door opens.
3. Dump the meltwater before you shake. Pour the cubes into the tin, tip the water out, then build the drink. That one second removes the film that starts the dilution.
4. Use more than feels right. Three-quarters of the large tin. If the ice is weak, quantity is how you compensate.
5. Crack a big cube rather than using small ones. The back of a bar spoon on a 2-inch cube gives you dense irregular pieces, which beat hollow crescents every time.

A warm tin is the hidden version of the same problem. Steel pulled from a dishwasher cycle is at 50C or more, and it will melt the first cube before you have measured anything. Rinse the tin cold first - see how to clean bar tools.

This is the distinction that most quietly improves home drinks. The ice you shake with is a consumable - it does the work and then you throw it away. The ice in the glass is a component of the finished drink, and it has an entirely different job: melt as slowly as possible so the drink holds its balance for twenty minutes.

So a shaken drink served over ice gets 1-inch cubes in the tin and a single large rock in the glass. A shaken drink served up - a daiquiri, a sidecar, an espresso martini - gets the same cubes in the tin and no ice at all in the glass, which means the glass itself has to be cold. Freezer, five minutes, every time.

How to shake a cocktail covers the shake itself, what size cocktail shaker covers the tin, and best clear ice molds covers making the single large rock for the glass.

Two cases. A dry shake - egg white, or the first shake of a whisky sour - uses no ice at all, because the point is emulsification rather than chilling; the ice goes in for the second shake. And a few drinks are supposed to be slushy: a swizzle, a julep, a tiki build poured ice and all into the glass. For those, crushed ice in the tin or the glass is the recipe rather than a mistake.

Everything else wants 1 to 1.25 inch cubes, dense and dry, filling the large tin to about three-quarters. How to make crushed ice covers the exceptions properly.