Also called superfine sugar. It is pulverized granulated sugar. It can be purchased or prepared at home by whizzing some granulated sugar in the blender.

Very fine crystals make this sugar excellent for sprinkling and including in recipes. It is known as caster sugar because it is suitable for placing in a caster - a jar or bottle with a perforated top, similar to a flour dredger. Uses: For sprinkling over fresh fruit or cereals or including in creamed mixtures, meringues and baking. To store: Keep in a cool, dry place for up to 1 year and once opened store in an airtight container to prevent the sugar from going hard or damp.

very finely granulated sugar that was formerly sprinkled from a castor

finely granulated white sugar

An often used term for superfine sugar.