I use the standard Wilton buttercream recipe that I learned in class (1 c. shortening, 1 tsp flavoring/s, 1 tbsp meringue powder, 1 lb powdered sugar), and it works perfectly for icing and decorating. My problem is, once the cake is decorated, the icing tends to crumble off when the cake is cut. I just made a basketweave-sided cake, and whole lines of basketweave and rope border fall off as the cake is cut. It's like it crusts a little too well, and breaks off. It's not an issue with the actual base icing, just with side decorations and borders. Why does this happen?

I tried using butter my 3rd week of class, and it tasted fantastic (no yucky shortening greasiness on the tongue), but here in South Florida, it got soft too quickly, and keeping the cake refigerated is usually not an option.

Is what's happening to my buttercream normal for an all-shortening recipe? Is there something I can do to help with the problem? Is there a different recipe that is easy to decorate with, and doesn't crumble off the cake?

Sorry for the long post...

Are you keeping the cake covered? If so and it's still happening, you can try leaving out the meringue powder and/or adding less powdered sugar.

Are you adding any liquid at all, water or milk? To me, it seems that the icing would dry out too quickly, or too much without a little added liquid.

perhaps trying a 1/2 butter 1/2 crisco recipe??? holds up well in the heat and the butter may prevent it from crusting too much.

1 stick butter
1 c crisco
2 lb bag of powdered sugar
1 tsp clear vanilla
4-10 tbsp water depending on desired consistency

I do add water, the amount varies depending on the consistency I need, but I did forget to mention that, didn't I? Oops!

I could keep the cake covered a bit more, so maybe that's the problem, or I will try the half butter, half crisco recipe and see how that goes.

Thanks, everyone!