what causes bulge on my cakes?
Like a bulge between the layers? The filling is too soft or too thick and the weight of the top layer just pushes it down. If you fill the cake, then put the top layer on and press down really firmly on it (not hard enough to rip the cake up of course) that will compress the filling and force it down to begin with, and it's unlikely to compress on its own so much.
ah, i do tend to put a lot of frosting in between the cakes, thanks a bunch!!
I find that if I don't let the cake settle long enough there can be a bulge. So my process is to stack and fill the cake as well as crumb coat it with a thin layer of buttercream. Then I will let it sit for several hours (I prefer overnight) before frosting and decorating it. Works every time!
My research has shown me that it, when cakes are all leveled flat and you still get bulging, it likely the icing you are using.
What's the recipe? Icings that have much liquid (upwards of 1/2 cup or so) tend to bulge. The liquid "wets" the sugar and turns it into a thick liquid. Gravity does the rest....the liquid icing will in time flow a bit due to the pressure from the layer above.
My icing recipe has no liquid, save maybe 2 tablespoons of whipping cream at most to thin is needed...and it's rarely needed....and I never have bulging. My old recipe had 1/2 cup water in it...and it bulged a lot!!!