Confectioners’ sugar is an essential for frostings and icings. The fine crystal size keeps butter creams smooth and can provide an attractive snowy dusting on doughnuts and other pastries. However, all is not lost if you find yourself out of this fine-textured sugar. There are several confectioners’ sugar substitutes that you can use in its place.
Your best bet: Make your own confectioners’ sugar
Confectioners’ sugar is simply white granulated sugar that has been finely ground and combined with a small amount of corn starch. You can do the grinding yourself. While your substitute will probably not be as consistently fine as the confectioners’ sugar bought at the store, it should be similar enough to do the job.
To grind your own confectioners’ sugar, you will need a blender or coffee grinder and a very fine sieve. Place white granulated sugar into the blender or coffee grinder and pulse for about a minute. Sieve the sugar until you have enough to complete your recipe. The sieving is necessary because there will still be both large and small crystals in the sugar. You want to get only the very finest of the crystals.
Mix in 1 teaspoon of corn starch for every cup of confectioners’ sugar you make. This will make it an even closer approximation of store-bought confectioners’ sugar.
A decent second choice: Larger grinds of powdered sugar
The standard confectioners’ sugar found in most grocery stores is 10x confectioners’ sugar. The 10x denotes the finest grind of sugar. There are other powdered sugar grinds available as well that are also indicated by an X. Since 10x is the finest, all of the others will be a lower number. For example, 6x and 4x powdered sugars have larger crystals which may make them a little harder to dissolve in a frosting, but that can be used to dust the tops of desserts with little to no difference in appearance or mouth-feel. They may actually do a better job than 10x sugar would, simply because they do not dissolve as quickly.
In a pinch: Powdered dextrose (glucose)
The full name of this sugar is dextrose monohydrate and it is one of the components in table sugar. Dextrose powder consists of finely ground crystals, just like powdered sugar. These crystals function in much the same way that confectioners’ sugar and other powdered sugars function. Dextrose is derived from corn starch much like corn syrup.
When using dextrose in place of confectioners’ sugar, you will have to be mindful of two things: the fact that it absorbs more liquids than regular sugar, and the fact that it is not as sweet as regular sugar. This means that you will have to use more liquid to compensate, while also decreasing the proportion of dry ingredients. Since it is only between 50 and 75 percent as sweet as regular sugar, you may also need to use more of it to achieve the same degree of sweetness.
Note that as with honey, dextrose burns more easily than regular sugar. If you are baking the dish after adding dextrose, be sure to reduce the temperature to between 300 and 350 degrees Fahrenheit.
Superfine sugar is also called caster (or castor) sugar in the UK. It offers a finer crystal size that is not quite as fine as those found in confectioners’ sugar, but that is still finer than those in regular granulated sugar. Even so, it can work for many of the same applications. Note that caster sugar does not contain corn starch, which means that can potentially affect the outcome of some recipes.