Hi all -
I iced my sheet cakes with my buttercream but once it crusts and I move it cracks. Totally uncool. What can I do?
thicker base under cake will help -- cake is flexing due to weight and size and not enough support.
I use 3 sheets for foam core glued together
plywood would also work, again at least 1/2 thick -- this will be much heavier than foam core tho'
Usually that happens if the cake board under the cake isn't strong enough. When the cake board is too thin, it allows the cake to move slightly and that causes the icing to crack. I recently began using 1/2" foam core under my sheet cakes and haven't had any problems since.
According to Marina Sousa, you can add a little vinegar to your buttercream to help prevent cracking. She says you can't taste it but I've never tried it.
Heavier board on the bottom is really the easier answer tho. I use MDF that I cut to size, covered with a food-safe paper or cake foil
ditto. Cracking is not a bc issue, its a support issue.