Tough Crust Factors
I recently made a loaf which was basically a JH Hamelman 5 Grain Levain, but with some added rye and spelt flour. About 10 - 15 % each. I made 2 loaves - gave one to my brother and kept one for myself. I noticed on bake day, fresh, it was amazing. Crispy crust. On day two, the crust had turned to very chewy and tough. Now, I like my crusts chewy, but this was a bit more than what one would call desireable. My brother said that his on day 2 was still nice. I hadn't tried it myself, so I can say if it was the same as mine or better. The difference between my loaf and his, was his proofed an extra hour while mine was baking. Would this be a factor as to why his was not as chewy tough?
What are some known factors in an overly hard, tough and chewy crust?
Thanks for the help in advance.