A fair number of recipes call for the use of caster sugar, including meringues, ice cream, breads, savory pancakes and curries. If you find that you do not have caster sugar because you have run out or are not able to find it in supermarkets, it can be easily substituted in a host of ways.
Caster sugar is sometimes referred to as castor sugar in the United Kingdom and is called superfine sugar in the United States.
The most important tip when substituting caster sugar is being aware of how the sugar will be used in your dish because this will determine the best type of substitution to make.
Homemade Caster Sugar
You can make your own caster sugar by using regular, granulated sugar. Simply measure out the required amount of sugar into your food processor and pulse for about 10 seconds until the sugar is superfine but not powdery. Allow the sugar to settle in the container for a few minutes before removing the lid.
If you are making a darker dessert such as a chocolate-based dessert, you can use demerara or dark brown sugar as a substitute. Again, pour the required amount of sugar into your food processor and pulse for about 10 seconds until superfine but not powdery. Note: using dark brown sugar will not change the taste of the dish, but it will change its color. Brown sugar and muscovado sugars can be used as substitutes for golden caster sugar as well.
If you prefer to use artificial sweeteners, these can also be made into caster sugar substitutes by pulsing the required amount of sugar sweeteners in a food processor until superfine.
Syrups or Honey
For pudding, pies and pastries, you can use maple or corn syrup as a substitute. If maple syrup is used in place of sugar, use 3/4 cup syrup for every cup of sugar. Honey is also an option, but take note, honey tends to affect the texture of baked foods. To use honey as a substitute for sugar, use 7/8 cup honey for every cup of sugar. When substituting with maple syrup and honey in baking, reduce the liquid in the recipe by 3 tbsp.