So then, when last we left off I was talking about ovens and heat…wasn’t I? My thought was that since the vast, vast majority of folks out there don’t have brick ovens taking up large sections of their back yards, I’d demonstrate how to make your own home oven more like a big hearth. It isn’t very hard to do and it absolutely will improve the quality of your bread. More heat and more moisture are what it’s all about.
But my oven gets hot, Joe, what’s the difference? The difference is in the kind of heat. Though I’m no physicist, it’s my understanding that brick ovens offer three kinds of heat to the baker: conductive heat, convective heat, and radiant heat. Conductive heat basically means surface-to-surface or mass-to-mass heating: heat energy stored in the brick floor of the oven is transferred directly to the bread. Convective heat is the type we all hear about on oven commercials. Basically it means hot, moving air currents that collide with the bread. Think of radiant heat like a flashlight, which in a nice hot brick oven comes from all directions except the door. All combined, you get a huge dump of heat energy into the loaf, causing rapid expansion of the bubbles inside. What results are the nice big holes (or “open crumb”) so many bread bakers prize.
Commercial ovens give you those types of heat, though in lesser amounts. There’s little conductive heat, since the bread sits in a pan on a rack, basically suspended in space. There’s also not as much radiant heat, which mostly comes upward from the heating element below (in most ovens), and to a small extent the top and sides (though they’re usually made of rather thin metal). Convection is about the same as a brick oven, though it can be better if you’ve got a convection oven and the fans are turned on. Yet that advantage can’t really make up for the overall deficit compared to an oven made of brick. Significant improvements, however, can be made.