Has it ever happened to you, when you were making a cake whose recipe demanded caster sugar, yet you only had powdered sugar at home (or vice versa)? Can we use caster sugar and powdered sugar interchangeably? Sugar, in any of the forms, indeed tastes sweet, but different forms of sugar may have different attributes and properties – which then may affect the result of your cake. Hence, knowing which is what and why is important.\
Furthermore, you may even get more confused with the different names of sugar forms: caster sugar, castor sugar, confectioner’s sugar, superfine sugar, powdered sugar, frosting sugar, icing sugar. Before somebody bangs their head against the wall, let me tell you that many of those names are actually the same things.
Caster sugar features fine granules of sugar with quick dissolving properties. Compared to regular granulated sugar, caster sugar has tinier particles. Hence, caster sugar is often labeled as superfine sugar. In addition, it is sometimes spelled castor sugar, too. Caster sugar is usually used by bartenders and bakers, and is used to make meringues and beverages.
Powdered sugar, also known as confectioner’s sugar, frosting sugar, and icing sugar, is extremely fine sugar. It is even finer than caster sugar. It can be ground 4X, 10X, or 14X. The higher the grind, the smaller the particles and the faster they dissolve. More often than not, powdered sugar contains cornstarch, which functions to prevent the sugar particles from clumping. Often used by bakers, it is best suited for whipping cream and cake icing.
Caster Sugar vs Powdered Sugar
|Caster Sugar||Powdered Sugar|
|- Also known as castor sugar and superfine sugar||- Also known as confectioner’s sugar, frosting sugar, and icing sugar|
|- The texture is finer than regular granulated sugar, but coarser than powdered sugar||- The texture is finer than regular granulated sugar and caster sugar|
|- Dissolves more easily than granulated sugar, but not as easy as powdered sugar||- Dissolves faster than granulated and caster sugar|
|- Doesn’t use cornstarch||- Contains cornstarch|
|- Used for meringues, cakes, and beverages||- Used for cake icing and whipping cream|
So, caster sugar is the finer version of granulated sugar. Meanwhile, powdered sugar has an extremely fine texture, with smaller particles, and often contains cornstarch.