Powdered sugar

Powdered sugar, also called confectioner's sugar or icing sugar, is a finely ground sugar made by milling normal granulated sugar into a powdered state. It usually contains a small amount of anti-caking agent to prevent clumping and improve flow. Although most often produced in a factory, it can also be made by putting normal sugar in a coffee grinder, or crushing it by hand in a mortar and pestle.

In industrial food production, it is used where a quick dissolving sugar is required. Domestically, it is principally used to make icing or frosting and other cake decorations. It is often lightly dusted onto baked goods to add a light sweetness and subtle decoration.

Powdered sugar is available in different degrees of fineness, most commonly XXX, XXXX, and 10X, with more Xs indicating finer grains. With finer particles more moisture is absorbed, which results in caking. An anti-caking agent is generally added during grinding, typically corn starch, or tricalcium phosphate, at 3% to 5% concentration, to absorb moisture and improve flow by reducing contact between sugar crystals.