Are baking stones a must have?
Currently, I bake on a round pizza pan, I have a small aluminum roasting pan filled with river rocks for steaming purposes. I only bake sourdoughs and my general method is to preheat the oven at 500º with pizza pan and river rocks inside for about 45 minutes. The oven is nothing special, it's a basic gas oven that came with the house, it doesn't even have a timer.
Just before I'm ready to bake, I put 3 wet terry cloth rags in the microwave for 3-4 minutes to get them steamy, then I pour about a half cup of boiling water over the stones, and close the oven to let it steam up a little bit. When the rags are done, I pop those in the oven on top of the rocks, close the oven.
I get my loaf out and slash (I've been retarding my loaves overnight for the final proof). I pop the loaf in the oven and quickly pour another half cup of boiling water over the rags. At 15 minutes I take out the rags and reduce the oven temp. to 400º, then continue to bake for another 20-30 minutes.
I get a really good oven spring with this method. I'm still trying to figure out the right temperature and rack location for my oven. I can cook a pizza on the oven floor with no problems, but with my bread on the lower two racks the bottom of the crust sometimes burns a little bit even though the rest of the bread is perfect.
I guess I'm just wondering, what if anything, would I benifit from a baking stone? Would it help with my occasional bottom burning? I'd still have to preheat at least 45 minutes right? Would I be able to cut out some of my steaming steps?
There seems to be lots of different methods of baking the hearth or artisan type breads, and pizza stones seem to be a common method, baking stones are just another, and many people improvise with unglazed floor tile or even unglazed terra cotta pots from a nursery. I am using a Thai food pot with a lid that I soak in water, made out of unglazed terra cotta, for my sourdough breads and am just loving how they come out. Maybe if you put the pizza stone on a higher rack it would keep the bottom from burning? I use the soaked pot lid to steam & my bread is in a curved pot, so sometimes my bottoms aren't quite as crispy & brown as I'd like them to be. Have you tried Susan's method of using an upside down bowl to trap the steam? If you have the right size bowl to fit on your pizza stone that might make things easier.
Sounds like you have a good grasp for technique.
The benefit of a stone (or cast iron or thick sheet steel) is that the additional thermal mass helps with the overall temperature stability in your oven.
Stone takes longer to heat up but holds heat well. If your bread is overbaking on the bottom, a stone probably won't help, but as you mentioned rack position and oven temp will.
Your steaming method is great and is the same as/similar to several recommended by other users on this site. You do get great oven spring. Now about the bread burning on the bottom - you mentioned that you have a gas oven. The gas ovens that I have worked with in the past have the heat coming from the oven floor and then rising upward. Depending on the location of the thermostat (in the middle or near the top of the oven?), the lower shelves are closer to the heat source and may be hotter than the indicated temperature, thus the burning on the bottom of the loaf if you cook on the bottom shelf. If you raise the cooking shelf to the middle of the oven and possibly drop the temp by 25 degrees as soon as you put the bread in, you may well eliminate the problem.
Personally, I use a baking stone but will let others talk about the pros and cons of them. In any event, even with a baking stone you would still have to preheat the oven as you do now and you would still want to go through all of your steaming steps to keep the bread crust moist and soft during the first 10-15 minutes of the bake so that it can expand where you want it to expand. Good luck.
Like Cranbo said, baking stones help keeping the oven temperature stabile. Especially if you are baking several loaves at once, like I do, you don't loose so much heat, when you open the oven to load and rotate the breads.
I use unglazed quarry tiles that were leftovers from our construction (unfortunately Home Depot and Lowe's don't carry them anymore). Pizza stones, if they are not very thick, crack very easily at high oven temperatures, I broke two already.
Steaming or no steaming has nothing to do with the use of a baking stone. If you want to achieve a thin, crisp crust, you have to steam (or use a Dutch oven or other cover).
Karin