I've read the recent posting on cracking so this is sort of a sister post to that...

I've noticed my buttercream (overnight at room temp) doing this odd thing where along the side of the cake there is a lump (I assume bubble of some sort under the frosting, the frosting actually pulls away from the cake in that little spot) and a crack in the middle of that lump. almost like an air bubble. The cake is room temp when I frost, stored at room temp. NO IDEA. I make dozen of cakes a week and this only happens to a few and I can't figure out the common factor. do you think this is a "need more fat fix". I also use crisco and butter recipe.

Thanks!

There isn't a common factor.

If you read up past posts on the nasty icing bubbles, you will see that it can and has happened in many different situations.

I've had the same thing happen, with the cake being at room temp the whole time. To me the only common element I have found is that it seems to happen more in the spring and fall.

Do you let your cakes settle any between the filling/crumb coat and the actual icing?

I could let them settle more.... I am always in such a rush, something I just stack and frost right away! I'll try to get better prepping ahead. Oh, and I've only noticed them since the weather started to change....BUT I kept it 70 degrees all the time. I know the humidity changes like wild though!