Lately the crust of certain of my breads are cracking open far more than is normal. This is true for both sourdough and European-styled hearth bread (Italian-style loaves/68% hydration). I seem to be getting more rise from these loaves than in the past, and I guess the skin of the dough is not able to stretch sufficiently to accomodate the amount of rise I am getting. These loaves taste wonderfully but do not have the classic look that I am accustomed to getting. I am not aware of my changing anything that would cause this, and it is not happening with my Pain De Campagne loaves. Any ideas?