Also known as "superfine sugar" or "baker's sugar", caster sugar is the same as regular granulated sugar but ground to an extremely fine form with a texture somewhere between standard white sugar and icing sugar. Caster sugar is not quite a powder and is more like a very smooth sand. Because of its very fine and tiny sugar crystals, caster sugar melts and dissolves more quickly than regular sugar, and for this reason is a great choice when incorporating sugar into a cool or lukewarm mixture, or a recipe in which the finished product is meant to be as smooth as possible.
Golden caster sugar is a fine granulated sugar that is made from unrefined sugarcane or beets. It is popular in the UK for its color, which is a golden brown, and it has a slightly buttery flavor. In the US, and the rest of the world, the best substitute is regular white caster sugar.
The fine results of caster sugar can be mimicked by adding regular granulated sugar to either of these two substitutes.
If you're wondering why "caster sugar" isn't ringing any bells, it's because it's more commonly used in England for cookies and cakes. It it also a lot tougher to locate in the United States. Caster sugar is sometimes available at your local Walmart, however, you may need to visit a specialty foods store to find it. If you're not pressed for time you can always purchase it online. If you're like most people and you don't have superfine sugar lying around, the good news is you can make it yourself by finely grinding regular sugar using a kitchen appliance you already own!
Start with slightly more regular sugar than the recipe calls for. Some of the granulated sugar will turn to dust as it's being ground, so you'll want to account for that when you're measuring out how much to make.
Cover up your grinding appliance with a towel to protect from making a sugary-mess of your counter.
Turn your appliance to its highest setting for 1 to 2 minutes until the sugar is very fine, almost like a powder or extremely fine sand.
Before lifting the lid, allow the sugar dust to resettle into the superfine sugar for 20 seconds. Remove your freshly-ground sugar and get baking!
Since the grind in caster sugar is so fine, it dissolves quickly and smoothly into cold liquids and is a great beverage sweetener. Bartenders, for example, will often use superfine sugar as opposed to granulated sugar when making syrups and cocktails. See how to make your own caster sugar simple syrup here!
Caster sugar is great for sprinkling over foods like fruit, cereal, and pastries. Because it melts and incorporates quickly, superfine sugar is often listed as an ingredient for creams, meringues, puddings, soufflés, and sorbets. If a recipe specifically calls for superfine sugar, it's generally for a reason. Using regular sugar instead will result in the same level of sweetness, but the texture of your end result will likely be grainier and less smooth.
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