castor sugar

Castor sugar, also known as caster sugar or superfine sugar, is a refined white granulated sugar with an exceptionally fine crystal structure, derived from sugar cane or sugar beets through a standard crystallization and grinding process. The crystals are smaller and more uniform than those of standard granulated sugar, typically measuring between 0.5 and 1 mm in diameter.

This fine texture dissolves rapidly in liquid and cream, making it superior for applications requiring smooth integration into wet or cold mixtures. The refined granulation produces a more elegant finish in baked goods and provides better distribution of sweetness in beverages and desserts. Castor sugar is functionally and chemically identical to standard granulated sugar—both are sucrose—but the particle size difference imparts practical culinary advantages.

Castor sugar is the preferred sweetener for meringues, mousses, soufflés, and whipped cream desserts, where its fine crystals dissolve quickly into delicate foam structures without grittiness. It is widely used in British and Commonwealth baking traditions for cakes, cookies, puddings, and custards, and is essential in cold desserts and cocktails where rapid dissolution is critical. The ingredient is also favored for dusting over pastries and fresh fruit. In professional patisserie, it is standard for any preparation requiring smooth texture and uniform sweetness distribution, particularly where crystalline grittiness would compromise the final product.