Cosmopolitan glasses

Start with the shape. The V-shaped martini glass is the classic from the New York bars where the cocktail made its name: wide, shallow and dramatic, but also the model you spill from soonest once you start walking. The coupe has a rounded bowl with a lower centre of gravity and sloshes less, which counts behind a busy bar. The Nick & Nora sits between the two, with a small tulip-shaped bowl that holds the aroma better than either of the others.

Then the capacity. A cosmopolitan comes to roughly nine to eleven centilitres once diluted in the shaker, so a glass of 15.5 to 21 cl looks nicely full without anything going over the rim. The larger sizes of 24.5 and 26 cl are meant for bars that pour more generously or use the same glass for several cocktails; the 35 cl bowl is really a presentation glass. Finally, look at the thickness of the stem. A thick, solid stem feels clumsy but survives a dishwasher cycle that a thin stem will not.

Chill the glass first. Five minutes in the freezer, or a minute with ice cubes and a splash of water in it, then tip out the ice water and shake the glass dry. A cocktail stays noticeably colder in a frosted bowl, and with a drink served without ice that is the difference between a good and a mediocre cosmopolitan.

Shake the cocktail itself hard, because there is citrus juice in it and that needs air. Fill the shaker generously with ice, shake until the outside frosts over, then double strain: through the shaker's own strainer plus a fine tea strainer. Without that second strainer, ice shards float on your drink, melt within two minutes and water down the flavour. Work with four centilitres of vodka, two of cranberry and one and a half of lime and you are on the classic ratio from the cosmopolitan recipe. For a dry martini you use the same glass but stir instead of shake.

Nearly all stem breakage happens in one place: the join between stem and bowl. That is the thinnest cross-section and where the stress concentrates, and a glass you pick up by the bowl and twist free from a sticky surface will break right there. So always pick a cocktail glass up by the stem or the foot, even when it is empty.

In the dishwasher, place stemware loose, with space between pieces, and never pressed against each other in the same row. A short glassware programme at no more than fifty degrees is enough, because cocktail glasses carry no grease, only sugar and citric acid. Store the glasses upright afterwards, bowl up, so the fragile rim rests on nothing. Machine-pressed hospitality glass from Arcoroc and Royal Leerdam is clearly more forgiving here than thin crystal glass from RCR or Bormioli Rocco.

If you are after the V-shape beyond this one cocktail, all the martini glasses are gathered in a wider range. The rounder models sit with the coupette glasses, and the small tulip bowl with the Nick & Nora glasses. If you would rather see the whole picture before choosing a shape, start at the cocktail glasses, where the low and tall models are too. And since a cosmopolitan without hard shaking is nothing at all, one of the cocktail shakers with a built-in strainer is the most sensible addition.