The thing about wood is, size matters. Or to be more accurate, surface area. To get a wood-fired oven ready for baking, you want to get as much heat into the masonry as you can as fast as you can. Because the thing about heat is, it dissipates. Even in a big 8-foot-tall mass of brick and stone, heat will begin to dissipate right after your fire reaches its peak heat. Maintaining a low burn after a large conflagration, therefore, is a waste of both heat and fuel. In an ideal world you want a big bright fire followed by a rapid die-down so you can scoop out the ash and get ready to bake.
Big thick logs that burn long and slow aren’t a help here. It’s the surface area you see…they have very little of it relative to their mass. Which means only so much of the log can be on fire at any given time. Thus short, slender logs are the way to go, “faggots” as they were once known (is there any way to talk about wood that isn’t a double-entendre?), which burn bright and hot, leaving no chunks of ember behind. Just ash. Bakers have historically used pine for this. Today people use everything from hardwood branches to broken up shipping pallets. Whatever you’ve got access to, man.
So then, what’s the best way to fire a brick oven? As I’m learning, by building a small fire out of kindling in the front of the oven, then feeding it with small 2″-thick logs for about the first hour until it really gets going. That’s the point at which you “load” the oven with larger pieces of wood. Nothing bigger than about 4″ thick mind you, but they can be long. You basically stuff the oven full, criss-crossing the logs over one another as high as you can reasonably go.
At which point something rather nifty happens. A sheet of flame rises in the front of the oven where the masonry is good and hot, then slowly works its way back through the oven spreading heat through the enclosure as it goes. A burn like that takes about 2 1/2 hours in my oven, and when it’s over there’s not much but ash left behind. At that point it’s time to spread what embers remain evenly over the oven floor to encourage them to burn down, about another half an hour, so they can be either pushed aside or (carefully) scooped out. All I need to do then is put the oven door on and wait a little while for the temperature to even out and come down to baking range.
What happens then? I don’t really know since I haven’t been able to match this timetable to a rising schedule, which is the next great trick: timing the bread rise for the moment that the oven is at the right temperature. Did I mention that all this is hard? It really, really is.