Regular contributor Hans writes in with this comment on my “hearth oven” posts:
Call me a skeptic. It’s important to preheat your oven to capture every last joule, but then it’s ok to open the oven door 3 or 4 times and spray relatively cold (even if it’s tap-hot) water into the oven? Do you realize how effective a coolant vaporizing water is? Certainly spritzing the side of the oven will negate that extra 30-45 minutes of preheating, especially on most cheap ovens which just have some metal (which quickly gains and loses its heat) and insulation.
My (unproven) thoughts on the matter are get an oven-safe pan or pot of water boiling and put it in with the bread, and have the oven temperature cranked right up as high as it goes even if you turn it down after putting the bread and boiling water in. That’s as good as I think you can get without injecting actual steam, or creating an enclosed
space (a la dutch oven). Me, I just go for the preheated dutch oven – easiest and most reliable – but it does put a damper on creative shapes. Its cast-iron goodness also holds quite a bit of heat and radiates from all sides.
Oh you engineering types and your insistence on consistency! There’s no doubt that opening the oven door lets heat out, and evaporating water does rob your oven walls of some of their heat. It’s not a perfect system. However I think it works the best relative to the others I’ve tried. Pans of evaporating water, in my opinion, give off too little steam in the early stages of crust formation, then too much later on, when a dryer environment is what you need to keep that crust crispy. So I’m a spritzer.
Heat loss is of course a valid concern. Most serious home bakers I know try to minimize it my introducing as much tile (or brick) as they can to their ovens, counting on the stored heat to offset the effects of opening of the oven door. Yes, if you want to be entirely consistent, a dutch oven is an effective strategy. It mimics a brick oven quite well, radiating heat from the walls and locking in the steam that the bread itself gives off as it bakes. However as Mr. Hans points out, this limits a baker greatly in terms of loaf shape. You’re mostly stuck with larger boule (ball)-shaped breads, and I’m too much of a crust man to be satisfied with that. Baguettes, with their high crust-to-crumb ratio, are pretty much my personal ideal. I shall therefore remain Mr. Spritz.