How to Make Powdered Sugar

Powdered sugar -- also called confectioners' sugar and icing sugar -- is a staple ingredient in baking. If you are making cakes, cookies, icing and glazes, powdered sugar is a necessary ingredient that cannot be substituted with white granulated sugar. If you run out of the powdered sugar while in the middle of baking, there's no need to wash up and leave your kitchen. You can simply make your own powdered sugar at home. In two minutes, you'll be back to baking your original recipe. Read the steps listed below and learn about how to make powdered sugar.

Here's what you need:

  • 1 cup granulated sugar
  • 1 tablespoon corn starch

Here's what you do:

  1. Check your recipe, to see how much powdered sugar you need.
  2. Measure out that amount of granulated sugar -- 1 cup of granulated sugar will make 1 cup of powdered sugar.
  3. Add 1 tablespoon of corn starch for every 1 cup of granulated sugar. The corn starch won't alter the taste of the sugar, but it will prevent the sugar from clumping [source: Domino Sugar]. Those allergic to corn starch or those who observe Passover can substitute the corn starch for an equal amount of potato starch [source: Martha Stewart].
  4. Combine the sugar and cornstarch in a blender or coffee grinder. Allow the ingredients to mix for approximately two minutes, until the sugar has turned to a fine powder.
  5. Use the powdered sugar immediately in baking recipes and glazes, or sprinkle it on top of waffles or French toast. You can store your powdered sugar in an airtight container in a cool, dry place. It's best not to store powdered sugar in the refrigerator because moisture will make it clump together, and because it can absorb odors [source: C&H].