Superfine sugar is the sugar that dissolves: two teaspoons muddled with lime wedges in a Caipirinha melt into the juice in seconds, where granulated sugar would stay gritty and powdered sugar would turn to paste. It is the right sugar for any drink that is muddled or shaken with dry sugar rather than syrup, which is most of the Brazilian family and a good deal of the nineteenth century.

What is superfine sugar?

Granulated white sugar milled to a finer crystal, called superfine or bar sugar in the United States and caster sugar in Britain, the crystals about half the size of ordinary granulated sugar so they dissolve quickly in cold liquid without heat. It is not powdered (confectioner's, icing) sugar, which is ground to a dust and cut with cornstarch, and which makes a drink cloudy and chalky. Before simple syrup became the bar's default sweetener, sugar went into drinks dry: a teaspoon shaken into a sour, a lump muddled in an Old Fashioned, two spoonfuls crushed with lime in a Caipirinha. The Brazilian drinks kept the habit because the sugar muddled with the lime also helps press out the peel's oil, and because a Caipirinha made with syrup tastes thinner. Superfine sugar is also the sugar of the Cherry Bounce and of any infusion, since it dissolves in spirit without warming.

What it does to a drink

Pure sweetness, like simple syrup, but it adds no water, so the drink is a little stronger and more intense than the same recipe made with syrup, and it leaves a faint texture that the Caipirinha family relies on. Because it dissolves in the juice as you muddle, it draws out more from the fruit. It pairs with lime and cachaça above all, with vodka and rum in the Caipiroska and Caipirissima, with egg white in a sour where sugar helps the foam, and with cherries and whiskey in a Cherry Bounce.

How to use it

For a Caipirinha, two teaspoons over the lime wedges in a rocks glass or shaker, muddled firmly until the sugar is wet and the lime has given up its juice; then the spirit and ice. For a sour, a teaspoon shaken hard with the citrus before the spirit, or dissolved in the juice first with a stir. For an infusion, dissolve it in the spirit by shaking; it goes in cold. To make your own, pulse granulated sugar in a blender or food processor for thirty seconds, stopping before it turns to powder. A teaspoon of superfine sugar is roughly a quarter ounce of simple syrup in sweetness.

Substitutes

Simple syrup, a quarter ounce per teaspoon of sugar, adding a little dilution. Granulated sugar, muddled a little longer and shaken harder; it works but may leave grit. Demerara or turbinado sugar for a brown-sugar Caipirinha, which is traditional in parts of Brazil. A sugar cube crushed. Not powdered sugar, which clouds and pastes.

What to buy

A box of superfine or caster sugar from any grocery (Domino, C&H, or the baking aisle's "baker's sugar"); or make it from granulated in a blender. Organic cane superfine sugar has a faint caramel note that suits rum drinks.

Storage and shelf life

Indefinitely, in a sealed, dry container; it clumps if it gets damp. Keep a small shaker-jar of it beside the bar for sours and Caipirinhas.

Cocktails with superfine sugar

The Brazilian family: the Caipirinha, the Caipiroska and the Caipirissima. The infusion: the Cherry Bounce. Every drink that uses superfine sugar is listed below.

Questions

Superfine, caster or powdered? Superfine and caster are the same thing: fine crystals that dissolve cold. Powdered sugar is ground to dust with cornstarch and is wrong for drinks.

Can I use syrup in a Caipirinha? You can, but the drink is thinner and the lime gives up less; two teaspoons of sugar is the real thing.

How do I make superfine sugar? Pulse granulated sugar in a blender for thirty seconds.

How much sugar equals a quarter ounce of syrup? About a teaspoon.