I almost always use buttercream on my cakes. Most often, I have to make the buttercream look as smooth and as much like fondant as possible, which I can do very well. When I go to move and deliver the cakes the buttercream gets fine little cracks in the surface, which I usually don't get any complaints about, but it really irritates me. I need some advice!
Those hairline cracks are usually the result of the board under the cake not being strong enough and it flexes under the weight of the cake when it's being moved around. Even just a little flex will cause the cracks.
Having the cake on a thicker base board---foamcore (3/16th or 1/2 inch) or several corrugated boards taped together--will help a lot.
I make a crusting buttercream, too, but I also add in 6-8 oz. of heavy cream per 2lbs. of PS, so it's fairly moist. It's much less prone to cracking.
Thank you! I thought it was because of the board flexing and I have been gluing 2 cake drums together and it doesn't help, it still cracks. I even used a 1inch piece of plywood, recently, for a guitar cake and it still had little cracks in it. It really irritates me. Oh well I will keep trying.
Well, since the flexing issue is covered, then I'd go to the cake itself.
Do you allow your cakes to rest & settle at room temp before applying the final icing coat? If not, a cake shrinks a bit as it "ages" and that would cause it to crack.
Are the cakes still cold or slightly frozen when final iced? Again, an issue of expansion as the cake warms.
Are the cakes refrigerated or frozen after final icing? If the icing recipe is somewhat "dry", it may crack as the cake comes back to room temp.
I'd suggest adding a bit more liquid--I use heavy cream as the additional fat helps as a preservative--and see if it helps to resolve the problem.
I am going to try adding cream and see how that works. Thanks again!
Hope it works out!