Caster sugar is called "superfine" sugar in the United States. Do not confuse with confectioner's (powdered) sugar to which cornstarch has been added.
Caster sugarflouricing sugar / confectioners' sugar / powdered sugar
My recipe uses 6 oz icing sugar (powdered) and 3 oz of caster sugar and it works every time but I think the icing sugar (powdered) is important. Just checked 2 other recipes on www and they both use both types of sugar so I guess you should go and get some.
Caster sugar is similar to powdered or confectioner's sugar in the U.S. which may be substituted without problem. Raw sugar would need to be processed in a spice or coffee grinder or in a food processor until very fine and powdery before being substituted for caster sugar.
I have tried it and dosent make much of a diffrence!
No, its not, icing sugar is a fine powder whereas caster sugar is grainy crystals. Chemically they are probably the same, but the grain size is different. Caster sugar and granulated sugar are the same though I think.
Confectioners sugar and powdered sugar are the same, so yes, you are using the same thing regardless of what the recipe calls for.
YES
Yes
Yes It has been procesed in the same way!
Yes, you can use caster sugar instead of granulated sugar. However, be careful on the measurements. Use a little less caster sugar. Caster sugar is finer granulated sugar. It is not as fine as powdered sugar, but it is in between granulated and powder. Caster sugar dissolves more easily,so it is very beneficial in making meringues.
No. Powdered sugar is sucrose. Out bodies can break it down to make glucose.