Bottom crust

Hello,

I’ve been baking using a Rofco B20

oven and feel I can improve on the bottom crust (it’s not terrible but it could be a little better - I’m just a bit obsessed about bread at the moment). It’s a little too hard. Does anyone have any tips? I usually heat up the oven for 2 hours at 250C (max) then when I load the loaves of sourdough (which have been proofing overnight in the fridge uncovered)I turn it down to 200C, spray generously with water and bake for 20 min. Then I open the oven door to release the steam and bake for another 25/30 min at the same temperature. I always shuffle the doughs around so they bake evenly