Powdered sugar

Powdered sugar (icing sugar in the UK) is white sugar ground into a soft, very fine powder. It dissolves almost at once, so it makes smooth frostings, glazes and icings without grit. It is also dusted over cakes, waffles and pastries, and used in some cookies, shortbread and French meringue toppings.

How to do it

To make your own:

1. Put granulated sugar in a blender or spice grinder. For every 200 g (1 cup) of sugar, add 1 tablespoon cornstarch if you want it to keep without clumping.
2. Blend on high for 1 to 2 minutes, until it is a fine, soft powder.
3. Let the dust settle before you open the lid, then sift it.

200 g of granulated sugar gives about 1¾ to 2 cups of powdered sugar.

How to use it

It has many names:

• Powdered sugar or confectioners' sugar in the US. Bags may also say 10X, which refers to how fine it is ground.
• Icing sugar in the UK, Ireland, Canada, Australia and New Zealand.
• Florsocker in Sweden and Puderzucker in Germany.

American powdered sugar usually contains a small amount of cornstarch, around 3 percent, to stop it caking. Icing sugar elsewhere often has a little anti-caking agent instead. Either works in the same recipes.

Sift it before use. It clumps in the bag, and lumps stay as white spots in a glaze or frosting. By volume it is light: a US cup weighs about 120 g, much less than a cup of granulated sugar.

For a simple glaze, stir 120 g (1 cup) of sifted powdered sugar with 1½ to 2 tablespoons of milk or lemon juice. Add the liquid a little at a time. It goes from stiff to runny very quickly.

Substitutes

You cannot use granulated sugar in a frosting or glaze. It stays gritty. Grind it as above instead. Superfine sugar (caster sugar in the UK) is finer than granulated but still not a powder.

How to store it

Keep it in an airtight container in a dry cupboard. Humid air makes it clump and harden.

Common mistakes

• Dusting a warm cake. The sugar melts and disappears. Wait until it is cool.
• Swapping it for granulated sugar by volume in baking. A cup of it holds much less sugar, and the starch changes the texture.

In recipes

You will see "2 cups powdered sugar, sifted", "250 g icing sugar" and "icing sugar, for dusting".