Pullman bread caved in on top
I have been baking Pullman sandwich loaves for some time - my kids are pretty much hooked on sandwich press grilled sandwiches and free standing sourdough breads don't cut it for this. More often than not (but not always, by all means) bread comes out looking pretty good and square out of the oven, then the top caves in while the bread is cooling. I cannot identify a pattern to this, sometimes it doesn't happen, probably 2 out of 3 times it does.
Needless to say, when the sandwich press cuts the slices diagonally, one section comes out bigger than the other and the jutting "points" don't get any cheese without custom carving the slices to fit this particular shape. It also bothers me because I don't believe it's called for and I am sure can be avoided with proper technique.
Can somebody point me in the right direction? The bread is a simple yeast based bread, enriched with milk, sugar, and butter. I use an Italian type 1 bread flour with ca. 13% protein content. Mixing in 50% of stronger (and whiter) flour (14+% protein) didn't seem to make much difference.