What did I do wrong? Middle of loaf didn't cook.
So here is what happened, I decided to make this loaf, the daily bread  again, the first time I did it last year it worked pretty much fine.
This second time though, does anyone know what may have caused my loaf to totally fail in the middle?
The outside looked perfect with it's brown crust and color. I cooked it as suggested, max oven temp, which is 550 for me, for 5 minutes then turned it down to 470 for another 15. It rose just as it was supposed to but once I cut into it the middle of the loaf was a big ball of dough, the middle was as if it wasn't ever even put in the oven.
I followed the recipe with the only change being 3.5 cups of flour instead of a pound as I don't have a scale. I used King Arthur's bread flour with SAF instant yeast. Had the poolish work over night for 8 hours and with the main dough I mixed by hand and did the French fold method four times over the course of three hours with the final resting for about an hour.
I ended up putting it back in the oven for 20 minutes after I had ruined it by cutting into it. In the end I had a large loaf of toast, but it was either doing that to salvage something or tossing it all out. A day later it is okay to eat, the crust and the exposed bits are burned, but digging in deeper to the loaf its fine.