What's the Difference Between Powdered Sugar and Confectioners' Sugar?

Think confectioners' sugar and powdered sugar are the same? Think again. The terms are often used interchangeably, but technically these two sugars are different. Powdered sugar is simply granulated sugar that has been ground to a very fine powder. Did you ever wonder what the "10x" on the label means? It refers to the number of times the sugar is processed and milled—in this case, 10!

Confectioners' sugar, on the other hand, is powdered sugar with starch added, to prevent it from caking as it sits. Most sugar companies use cornstarch, which helps keep the confectioners' sugar from melting into cakes, cookies, and other sweets, like Fry Bread, when it's dusted over their tops. A few smaller sugar producers, particularly those that offer organic varieties ($3.99, target.com), use other starches, adding potato or tapioca starch to their confectioners' sugar.

Some pastry chefs and other food professionals, like Stella Parks, author of BraveTart: Iconic American Desserts ($24.69, amazon.com), swear they can taste the difference between the starches. They insist that the cornstarch imparts a metallic taste to confectioners' sugar, or a chalky consistency. If you have also noticed this, you may want to do a side-by-side test and see for yourself.

Why Not Just Use Granulated Sugar?

Aside from the added starch, powdered and confectioners' sugar essentially perform the same function: to sweeten. These finely milled sweeteners are most often used in glazes and icings (which is why powdered sugar is known as icing sugar in the UK), and they dissolve much more quickly and easily at room temperature than granulated sugar does. When whipping cream, for example, confectioners' sugar is a better option than granulated, since it will dissolve easily into the chilled cream; this results in a better, less grainy texture.

How to Make Powdered Sugar or Confectioners' Sugar

It's easy to make your own powdered sugar from scratch if all you have in your pantry is the common granulated variety. Simply grind the granulated sugar in the bowl of a food processor or blender until it's a fine powder. To make confectioners' sugar, add about one tablespoon of cornstarch per one cup of granulated sugar before processing. The longer you grind it, the finer your powdered sugar will be.