If you bake using British recipes, you may find yourself in pursuit of exotic-sounding ingredients, such as castor sugar and double cream. Castor sugar is not the same as the granulated white sugar found on American grocery shelves—it’s much finer. But it’s not the same as powdered sugar, either. It’s somewhere in between. Luckily for Anglophile cooks, there are two easy options for recipes calling for castor sugar. One is to use superfine baker’s sugar, which is available from gourmet markets or even big supermarkets. Another option is to take regular granulated sugar and whir it in the food processor for 30 seconds, or until its volume is reduced by about a third, says Kelli2006. This method works particularly well if you want to use less-processed, golden-color turbinado sugar in your English baking. You’re unlikely to find it in a superfine version.
Finding an equivalent for English creams, however, is much trickier. English milks, creams, and butters are very different from their American counterparts, says smartie. The English versions generally are more yellow and have a higher fat content. Heavy whipping cream is similar to British double cream. Single cream, or pouring cream, apparently lacks an American counterpart, though—it’s much thicker than half-and-half, says cackalackie, and thinner than heavy whipping cream. And clotted cream has no American supermarket equivalent whatsoever. It’s a sort of boiled cream with a layer of film over the top, and it’s used mainly in desserts. Your only hope is a specialty store that sells British products.
Board Link: Different English Creams, Plus a Sugar Question