What size cocktail shaker do you need

A single shaken cocktail is typically around 3 to 4 ounces of liquid before dilution. A full ice charge for that is roughly another 8 to 10 ounces of volume. And then you need headroom for the ice to travel - if the vessel is full to the top, the ice cannot move and you are stirring badly rather than shaking.

The headroom column is what people miss. A tin filled to the brim produces a poorly chilled, under-diluted drink because the ice had nowhere to go, and it is far more likely to leak because the liquid is pressing on the seal.

The two sizes are chosen so that the small tin seats inside the large one at a taper that seals reliably. That is the primary reason for the pairing - it is a geometric fit, not an arbitrary pair of numbers.

The secondary reason is that the combination gives the right working volume for the one-or-two drink shake that constitutes most of what anyone makes, at home or behind a bar. Larger tins exist and they are heavy, awkward at arm's length, and rarely worth it.

The 18oz tin on its own is also useful. Used alone with a Hawthorne it is a perfectly good single-serve shaker, sometimes called a cheater tin, and it is lighter in the hand for a one-drink shake.

This is the recommendation that saves people money and it goes against instinct. If you routinely make four drinks, the intuitive answer is a bigger tin. The better answer is a second standard pair.

• You can shake both at once, one in each hand, which halves the time rather than doubling the volume.
• The weight stays manageable. A four-drink charge of liquid and ice in one tin is genuinely heavy at arm's length, and a hard shake with it is awkward.
• Redundancy. A pair in the sink does not stop the evening.
• Better drinks. Two properly filled tins with correct headroom beat one overfilled one, every time.

The exception is batching: if you are making eight of the same drink, pre-batch the liquid, then shake in portions. Shaking is the step that does not scale, and no tin size fixes that.

Fill the tin roughly two thirds with ice. Under-icing is the most common home-bar mistake in shaking, and it is counterintuitive: less ice means faster melting, because each cube is surrounded by more warm liquid and does more work.

Use ordinary freezer cubes for shaking. This is the one application where your good clear ice is wasted - it gets strained out, and the dilution it resists is dilution you actually want. Save the clear pieces for the glass. The cloudy sacrificial block from a directional mold is ideal shaking ice, which is one of the quiet advantages of making clear ice at home.

Once the tin is loaded, how to shake a cocktail covers the shake itself, which is where most of the texture in a shaken drink actually comes from.