It is thought that a wood-fired brick oven is necessary to form a complete crust around the loaf. Thus, the internal temperature doesn't get so hot as to kill all the beneficial microbes. Microbiologists tell us that after being baked, the microbes re-populate. Sourdough bread is said to be at it's best, nutrition wise, 3-4 days after being baked. 

Baking in Our Wood-Fired Brick Oven

Our oven was built in 1993. Interior dimensions are 6 by 8 feet. It was designed by Alan Scott*. It was the first oven built of this size that he designed. There is a layer of insulation separating the inner and outer masses of bricks. Every day we put a wheelbarrow-load of wood in the oven, bake it a while to get it real dry, and burn it. For the most part, we use scraps of kiln-dried hardwood lumber discarded by a carpentry shop. Sometimes we supplement this with dried hardwood from thinning out trees. We fire it up even on days we don't bake, to maintain a certain level of stored heat.
   There is no separate firebox, as the oven is the firebox. Before we bake, we rake out the ashes, and clean out the oven. We now have an oven that hopefully is pretty much the temperature we want, because there is nothing more we can do to raise the temperature that day. And trying to lower it is problematic.
   Since the oven will be steadily losing heat all day as we bake, we start off with the fast-cooking things: focaccia. In a hot oven, they'll sometimes cook in a couple minutes or so. If we tried to put loaves in this early, they would get a hard, dark crust without cooking enough inside.

   There are many variables to juggle, and every day's bake is a dance of trying to time everything so that most of our goods come out as close to perfect as we can manage.
  1. It takes judgment to know how much wood to put in the oven. Factors include outside temperature, residual temperature in the oven, and quality of wood. Then, the resultant oven temperature becomes a factor that affects all we do that day.
  2. The dough needs to be mixed to the proper degree of moistness, with water of the right temperature. This may sound simple, but in practice, it often ends up a little more wet, dry, warm, or cold than is ideal. Wet/warm dough "works" faster, becoming sticky and bubbly. However, if it is a cold, dry day, a wetter, warmer dough is more appropriate.
Keep in mind that this is the Ozark Mountain area, which has very variable weather, unlike the cushy conditions under which those San Francisco bakeries operate.
  3. The dough has to "proof" to a specific degree before it goes in the oven. If it's under proofed, a few too-large bubbles will form and blow out part of the loaf, or at least cause gaping holes that your jelly will fall through. If it's over proofed, the loaf will "crash", and be too flat. In either case, the bread will still be delicious and healthful, but won't look as good or make the best sandwiches. And since we usually are baking several different types of bread and other goods, there's a lot to keep track of. 
Since it is not economically feasible, we do not have air conditioning in the bakery. We are always manipulating the proofing process by wheeling the raw loaves to cooler (refrigerated) or warmer locations within the bakery, and hoping that, when something needs to go into the oven, there will not be a bottleneck of other items to bake.
  4. Often, the heat within the oven is uneven, despite our efforts to load the wood so that it heats evenly. Thus, the baker must work with this variable as well.

   The baker uses a "peel," sort of like a huge paddle, to move the bread into and out of the oven.

*Alan Scott
 Oven Crafters
 POB 24 
 Tomales, CA 94971
 (707) 878-2028