Here's a valuable perspective on the benefits of smaller, easier, cheaper, "faster-cooling" ovens, and a working baker's comparison w/the classic Alan Scott brick oven design (which isn’t always the best option for someone who wants to start small and simple).
The baker is Noah Elbers, who runs a small bakery in New Hampshire. There are some nice photos of him and his oven(s) on the web, but he's clearly spending his time in the bakery rather than on the computer -- hurrah! He does participate in the brickoven group on yahoogroups, which is where this comment came from. Copied here w/his permission...
-- Kiko Denzer
Re: Thermal Mass
Posted by: "noah elbers" breadwks AT sover.net
Thu Jun 26, 2008 4:40 pm (PDT)
When I was just starting out commercially I baked in a minimally insulated, 4-5" thick cob/clay oven. Here was my schedule and quantities just to give you an idea. This was a 5 foot deep oven, 3 ' wide app. but scaling up or down does not affect the number of loads much at all.
I would fire the oven from cold at 4:30 am. With three stokings (a brisk fire most of the time) the oven was fully saturated by 10:30 am.
2 loads of pizza (6 each load)
3 loads of bread (30-36 loaves each load)
2 loads of cookies or bars (totaling 150 pieces) sometimes pies, but not always, up to 15 on a regular basis, but over 100 at thanksgiving and christmas.
25 lbs of granola
By the end of the next day the oven had cooled enough to dry fruit like apples and plums, or herbs and tomatoes from the garden. Three days after sweep out the oven would be back to air temp.
Light up was very easy in this oven even from cool temps since it heated so fast, wood quantity was miniscule compared to my later AS design, and baking quality when I was within it's production capacity was better I feel.
When I built the AS oven, a 4X6, I routinely baked upwards of 700 lbs of dough on a single firing, (500 loaves) and a few times over 1000 lbs of food (bread plus wedding catering). Those things when properly heated can really hold on to some heat, but until they are nice and soaked with heat (something I didn't fully appreciate until after two years of baking in it) I don't think they bake very well.
When I retired my AS it took well over a month for it to come back to room temp. Amazing, but not useful for home bakers. The other downside of the AS design for home use I think is that once the thing is fully heated, you either need to wait a long time before it enters the lower temp zones better for more delicate things, or you need to have huge amounts of food to bake. The low mass oven will drop lazily but steadily once it is up to full heat, and in a matter of hours you can go from great pizza to great lemon meringue pie. Half an hour at pizza temp, 2 hours in the bread zone, 5 hours for cookies and desserts, 12 hours for braising and roasting, 24 hours for drying etc.
I have no agenda here, just ten years of small scale commercial baking experience that spans three ovens now. I was basically a home baker when I started, the business grew and required greater baking capacity, and I now no longer bake in a black oven. I think retained heat baking is fascinating, rewarding, and generally as good as any other cooking method. My motive in going on and on about this is to help people who have not baked with retained heat understand some of the heat dynamics of different thermal materials. Saving on costs, fuel, air pollution are tangential for me. The experience of using the oven is what I care about most, and I share this from my experience with the two types of ovens. (now three, but the Llopis is a whole different animal)
Orchard Hill Breadworks
breadwks AT sover.net
East Alstead NH 03602
(603) 835 7845