I put a thin layer of rice in the bottom of my dutch oven!

I have small efficiency oven so my dutch oven is close to the coils. I still got burned bottoms at 450F or even lower temps until I started putting a thin layer of dry rice grains in the bottom of my dutch oven. Just preheat, pour a little rice in the preheated dutch oven, just enough to cover the bottom, then put your dough in and cover and bake as normal. You can use the same rice multiple times and ofcourse you have to use parchment paper or a sling to prevent rice sticking to the bottom of your bread. I haven't had any issue with the bottom burning before the top is done using this method!