Used icing sugar instead of caster sugar in recipe - will it work?

[Tinkjon]

I just used icing sugar instead of caster sugar in some blueberry muffins. I, ahem, licked the bowl (salmonella, pah!) and the mixture it tasted odd, not nearly as sweet as usual. So can you not substitute icing for caster? I thought it was all the same sugar but just ground to different consistencies....?

yeah should be fine i would if id run out. let us know how they turned out

well if you have a grinder wizzy thing you can make icing sugar our of caster sugar so I don't see that it would be a problem

You probably only thought it tasted odd because you knew that it was "different" to usual.

Would be better to use ordinary sugar - icing sugar usually also contains cornflour.

Ok well they were definitely not as sweet. They were ok but far from tasty. Checked the ingredients of the icing sugar and it does contain other ingredients, so I suppose 100g of icing sugar contains less sugar than 100g of caster - which is why they weren't as sweet. I've still eaten 4, mind you

it will also behave differently when cooked than caster does due to it's consistency.