Hamelman's Oatmeal Loaf

This a first wheat loaf I baked in a long time. I used Hamelman's recipe with a couple of changes: I substituted 10% of the AP flour with durum flour and 12.5% (or half) of the whole wheat with whole spelt. I used a bit more water as the flours seem to be more thirsty in wintertime. The loaf came out very nice with a great, crackly crust which stayed that way for a couple of days. I think it was thanks to the Ankarsrum mixer as I never got this kind of crust in my old Cuisinart stand mixer. As nice as it looks, I think it opened up too much at the score as the crust separated from the crumb which can be seen in the cross section. I think I loaded it into the oven too early; maybe half an hour more proof would be perfect? Again, it's been a while since baking a wheat loaf. Overall though, I'm satisfied with it. It makes for very tasty sandwiches.