Hi All, I've noticed after making the Wilton Buttercream and decorating a cake after it sits for an hour or so and using the star tip method on the cake its HARD why is that? I am worried that once the cake makes it to the function the icng will be almost crunchy hard. Has anyone ever experienced this? If so please tell me what I need to do.....Thanks so much.

That's called crusting. Crusting is helpful when you're trying to smooth a cake. If you don't want it to crust, look for a recipe that has a higher proportion of fat to sugar. It doesn't crust hard enough to make eating it unpleasant though, at least not usually.

It probably seems "crunchier" due to the little stars. The icing is going to crust wherever the air hits it, which is alot when using the star tip. But, as Texas said, it's not unpleasant to eat. It shouldn't get so hard that people won't like it.

Personally I don't like the Wilton recipe. I use a crusting buttercream but it doen't crust nearly as "hard" as the Wilton. The use of the meringue powder is probably why it crust harder than mine because I don't use meringue powder.

I use Indydebi's Buttercream recipe. You can find the recipe here in the "most saved" recipes. I suggest that you try another recipe that doesn't use meringue powder and see the difference for yourself.
Her icing doesn't have to be refrigerated either.

Here's a tasty b/c recipe that is only minimally crusting (if extra meringue powder is added):

http://cakecentral.com/recipes/2019/whipped-cream-buttercream-frosting

No Crust b/c recipe:

http://cakecentral.com/recipes/1610/no-crust-buttercream-icing

HTH

Thanks Everyone for responding to my post, You guys rock!