Icing Sugar (Powdered Sugar)

Icing Sugar (Powdered Sugar): Nutrition and Baking Guide

Icing sugar — known in the United States as powdered sugar or confectioners' sugar — is white granulated sugar milled to an extremely fine, impalpable powder. Most commercial icing sugar contains a small quantity of anti-caking agent (typically 3% cornflour/corn starch in UK products) to prevent clumping. The very fine particle size means it dissolves almost instantly in small amounts of liquid, making it essential for smooth icings, glazes, and buttercream frostings that do not tolerate any grain texture. It also has a lower apparent sweetness per volume than granulated sugar because the particle size creates a different sensory experience. Icing sugar can be made at home by processing granulated sugar in a food processor or high-speed blender for several minutes until completely powder-fine, though homemade versions are typically less fine than commercial products.

Nutritional Value and Uses

Icing sugar provides 389 kcal and 99.8 g of carbohydrates per 100 g — nutritionally identical to white sugar. Use for royal icing (with egg white or aquafaba for piping and decoration), for simple glacé icing (mixed with a little water or lemon juice for doughnuts, buns, and drizzle cakes), for buttercream frosting (beaten with butter), for dust-finishing cakes and pastry (sifted over the surface), for macarons (the very fine texture is essential for smooth shells), and for meringue-based preparations. Always sift before use — lumps in icing sugar produce lumps in finished icing. In the US, "powdered sugar 10x" indicates the finest grind available.