restricted oven spring
I need a bit of help debugging my bread. I recently started trying to make bread again. The problem I'm having is that my loaf clearly wants to spring more in the oven as is evident by the final shape being tube like even though it started flat on the baking stone, but the crust won't let it expand enough.
Right now I've got about 75% hydration with 2:11 rye:white flour ratio. After shaping I place on my pizza peel and let rest for 40 min, then paint with cornstart+water and slash. Then into a 450F oven with a cup of 95C water (my oven reads in F and my water boiler in C) into a broiler pan right below the stone.
Below are some photos of my result. Any tips on getting the bread free enough to spring more? The water in the broiler pan doesn't last long, would replenishing it help?
The photos above come from approx 400g(~1lb) of uncooked dough