[baseten]

re: great British baking show - caster sugar is also hard to find in the US. (you can buy superfine but it only comes in very small bottles and is very expensive)

[fencepost]

C&H has superfine sugar in 4 lb packages, but they're the old cardboard milk carton style rather than the paper bag bricks used for granulated. They also have "Bakers Sugar" in fairly large print. Domino also sells it, but the grocery store site I checked only shows it in 12oz plastic bottles.

https://www.meijer.com/shop/en/pantry/baking/sugar/ch-superf...

[zwieback]

I've heard that you can make it in your food processor, takes a couple minutes. I've never tried it but Bob's Red Mill thinks it can be done.

[jfk13]

Or give it a bit longer and you've got icing sugar (or powdered sugar, as I think it's called in the States).

In virtually everything I've baked, though, it works fine to just use granulated. You may have to work a little harder to make sure it's truly all dissolved, that's all.

[ghaff]

The other thing you use caster/superfine sugar for is for some cocktails. Basically, it's a lot easier to dissolve in cold (or at least room temperature) liquids than regular granulated sugar is.

[zinckiwi]

Very true, I make homemade lemonade by just stirring it into lemon juice and cold water. No need to go through the simple syrup route.

[zinckiwi]

Icing sugar (at least as I know it in Commonwealth countries) also contains cornstarch/cornflour.

[dragonwriter]

As does US powdered/confectioners sugar.