Here are the suggestions from Cook's Illustrated for sugar substitutes using regular granulated sugar:
For Superfine Sugar - Run one cup plus 2 teaspoons of white sugar in the food processor for 30 seconds. This gives you 1 cup of superfine sugar.
For Confectioner's Sugar - Run 1 cup of white sugar and 1 teaspoon of cornstarch in a spice grinder or blender until powdered. They say a food processor won't process the sugar fine enough, and to process in two batches if your spice grinder is too small. Once powdered, sift the sugar through a fine-mesh strainer to remove any larger particles. This gives you 1 cup of confectioner's sugar.
For Brown Sugar - Pulse 1 cup of white sugar and 1 teaspoon dark molasses in a food processor until combined. If you need dark brown sugar, use 2 teaspoons of molasses. This gives you 1 cup of brown sugar.
How can this work? This article reminds us that these "fancy" sugars are nothing more than commercially processed white sugars. Making them at home is just a matter of duplicating the commercial process. They said that their substitutes worked just as well as the store-bought kind in their recipe testing.
Knowing these substitutes is useful not only for when we run out of a certain sugar, but also when we don't want to buy a whole bag when only a small amount is needed. Give it a try!
• This tip was published in the November/December 2008 issue of Cook's Illustrated. To subscribe to this magazine, visit their website!