It sounds simple enough...."add a cup of sugar"....but what does it mean when the recipe starts labelling the sugar...castor sugar...icing sugar...and what is the difference between the different brown sugars out there? All good questions so I thought I'd do a little research and share my findings.
Granulated Sugar - this is the one we normally use if the recipe doesn't stipulate any particular kind. It's also called refined sugar, white sugar, table sugar, sucrose
Castor Sugar - also spelled caster in some parts of the world, is called Super Fine in North America, fructose, fruit sugar. It's a finer grind than regular and dissolves faster too. It's most commonly used in making meringues and mixing into cold drinks. If you don't have any on hand and don't think you'll be using a large amount any time soon, you can make your own. Just put some in a food processor and grind it for a few minutes. Let the dust settle before taking the lid off.
Icing Sugar - is known as powdered sugar, confectioner's sugar and is a very fine powder that melts instantly. It's used in - obviously making icings, truffles and fondant, just to name a few of its uses. It melts instantly.
Brown Sugar - contains molasses, so the more the % of molasses, the darker the sugar and stronger the flavor.
For a more complete list of sugars and their substitutes, check out The Cook's Thesaurus.