CONFECTIONARY SUGARS
Confectioners' sugar is a term used in cooking to refer to any of a variety of refined sugars that have been finely ground into a powdery form.
CONFECTIONARY
It's simply another name for powdered sugar. In other words, confectioners' sugar (aka powdered sugar) is nothing but ordinary sugar. The only thing different about it is that it's been ground to a much finer consistency than table sugar, also called granulated sugar. (If sugar is called for in a recipe, it means granulated sugar. If the recipe needs powdered sugar, it will specify that.)
It does behave differently, however. Confectioners' sugar is easily dissolved in liquid, which makes it ideally suited for making icings and frostings. Additionally, confectioners' sugar can be used decoratively by lightly dusting it over desserts, baked items, and even fruit.
The word "confectioner" means someone who makes candies and other sweets. Confectioners' sugar is widely used in candy making and baking, and that's where the name comes from. (It's also sometimes referred to as 10X sugar.)
Confectioners' sugar is not the same as superfine sugar or bakers' sugar. These products are finer than granulated sugar but not as fine as confectioners' sugar.
PRODUCTS
CASTOR SUGAR
A fine grain refined sugar used extensively in baking and as an ingredient in powdered or granulated products.
Proven values:
Bulking agent
Enhances flavour
Contributes to texture
Quick dissolving
ICING (POWDERED) SUGAR
A milled refined sugar containing an anti-caking agent. Used primarily in the baking and confectionery industries.
Proven values:
Quick dissolving
Improves texture
Decorative and dusting purposes
Whips easily and increases the volume of foamy mixtures and creams
Increases the flakiness of numerous baked goods