Candice asked me if it was really necessary to preheat the oven for an hour before baking my no-knead bread. Here is what I learned from my latest experiment. I made three loaves yesterday to bring to a party. I turned on my oven (containing the covered baker) before shaping my first loaf for its second rise. My kitchen is quite cool, 68 degrees. The second rise took 45 minutes so the oven and container had preheated for 45+ minutes. I baked the first loaf for 30 minutes with the cloche on and then ten minutes with the cloche off (leaving the cloche in the back of the oven so it would stay hot for the next loaf). I have been reducing the oven temp to 425 degrees for the last 10 minutes because the crust gets quite dark if I leave it at 475. I like a dark bake but some of my eaters ask me if I've "burned" the bread.
After taking the first loaf out, I raised the temp back up to 475 and it took about ten minutes for the oven thermometer to register 475. The second and third loaves were baked with the same timing and temps and each loaf came out darker. Even though the oven registers 475 after 10-15 minutes of pre-heating it may not be optimal to get the best color and crust. For great crumb, you want the internal temperature of the bread to be 200-210 degrees when you take it out.