I've waiting about 10 minutes. Will it crust so that I can smooth it?
It will definitely crust....I have used it but I am not fond of the taste. For my latest cake, I tried mixing it with some regular can frosting to make it taste better but I still wasn't happy. I have a new cake to make in a few weeks, so I am searching for a new icing the crusts (preferable not BC because it's outside and will be hot)
I recently used this icing because my KA was broken and it took FOREVER to crust for me and didn't crust like I am use to. I usually make SugarShack's buttercream (the recipe is on this site). I holds up to hot, humid weather. I've also read on here that indydebi's buttercream holds up well to hot, humid weather as well. Good luck with the Wilton icing tonight - but try one of the above mentioned icings; I think you will like how it crusts and love how it tastes. HTH!