I have made about 75 cupcakes for a grad party for tomorrow. Later tonight I will make the colored buttercream and let it sit overnight so I get the "true" colors (red and blue... theme is "America"... the graduate is an exchange student who is going back to Russia on Tuesday).
Anyway, I make my buttercream with butter, pwd sugar, vanilla, and water. Will it be okay to sit out on the counter, covered of course, until I need to frost them in the morning? Should I put a damp towel over the icing like you do with royal, or just put it in an airtight container?
The party starts at 2 pm tomorrow. It's humid here right now, but my A/C is on in the house.

THanks! Maria

I see no reason why you can't just keep it in a covered container until you use it. I keep my cupcakes and cookies out on the counter after I make them and they are fine. There is nothing in your frosting that is perishable (the sugar will preserve the butter, I'm talking fruit) that would prevent you from doing this.

thank you! I always worry about the butter... didn't know that sugar would preserve it!

Maria