Powdered sugar is also known as confectioner's sugar or icing sugar. Powdered sugar is granulated sugar that is finely ground, with 3 percent cornstarch added to prevent caking.
Powdered sugar can come from cane sugar or beet sugar. The cane or beet sugar is processed from its raw form into granulated sugar. Next the granulated sugar is ground finely, and cornstarch is added as an anticaking agent. This further processing of granulated sugar creates powdered sugar.
The chemical formula for powdered sugar is C12H22O11, the same as for granulated sugar. The beet or cane sugars used are both sucrose sugars. The Union of Pure and Applied Chemistry (UPAC) name for powdered sugar is 2-[3,4-dihydroxy-2,5-bis(hydroxymethyl)oxolan-2-yl]oxy-6-(hydroxymethyl)oxane-3,4,5-triol. The Chemical Abstracts Service (CAS) Number is 57-50-1.
The label for powdered sugar can say 6X, 8X or 10X, indicating the number of times the sugar is processed. If it says 10X, for example, the sugar will have been processed ten times. The higher the number of times processed, the finer and more consistent the powdered sugar.
Many recipes for icing call for powdered sugar. The fine powder of the sugar allows it to dissolve more quickly than granulated sugar. It is also used to shake onto desserts to give sweetness without adding a grainy texture, as granulated sugar would.