Mud—earth, clay, the stuff under your feet—is a near perfect building material. Thousands of years ago, the first oven was made of mud. People all over the world still bake in earthen ovens, and the best ovens in the fanciest bakeries are often brick—which, after all, is made of kiln-fired mud.
If you’re a beginner, remember: even if you've never built a thing, your hands will show you how if you'll just start. We are all born into the tradition of building and making—it’s how we learn to tie shoes, cook eggs, swing a hammer, drive a car, and even how to play video games or surf the web (technology still begins, and usually ends, with our hands).
Building a mud oven isn't complicated. Pay more attention to what you're doing than to what I’ve written. Common sense and experience will be your best teachers. If you’re uncomfortable or feeling inexperienced, go slow. Take a break if you don't know what to do next. Solutions will come, and they will come easiest if you aren't in a hurry.
Granted, a good oven alone doesn't make good bread, which is why this book includes a simple introduction to sourdough. But a mud oven (with help from the baker) can produce perfect bread—equal or superior to the fanciest $5 loaf. I once took ten loaves of mud-baked bread to a wedding party for a German friend—five sourdough rye, and five sourdough wheat. All his German family and friends said, "this is just like home!" and asked where they could buy it. Some of them begged for a loaf to sustain them as they traveled in a land not known for its bread. I later made a portable oven (of lightweight pumice—on a four by eight foot trailer) to provide pizza for a local summer festival. My wife Hannah was head baker and a caterer friend provided dough and toppings; they made and sold about 250 pizzas per day, each one cooked to perfection in two to three minutes. People raved.
A mud oven is also a good place to make mistakes: undercooked lumps, and burnt or sandy crusts. But under-cooked dough can lead to grand discoveries: I sliced, toasted, and crushed up some under-cooked bread once because I loathe to throw away good (almost) raw material. I put the granules in jars on my shelves. One breadless morning, I decided to try soaking the stuff in milk with a little sugar—and heard echoes of Euell Gibbons praising the flavor of "wild hickory nuts." Now I always keep some on hand, even when I don't under-cook the bread. As for burning bread, I have learned that "burnt" is a matter of opinion. In some European countries, crusts that others might consider burnt are prized for the more intense flavor of the dark crust. And while charred is charred the world over, you can always cut away the burnt bits. Once, as an experiment (and because it was ready to bake and still rising fast), Hannah cooked a loaf in a 700 degree pizza oven. In less than ten minutes, the bread came out black, but we pared off the crust, and found it perfect inside. And of course, sometimes when you bake in a mud oven you get sandy grit in your crusts. Materials vary, and while most of them will work, some work better than others. When I get sandy bread, I just trim the crusts, bake in pans or on paper, or build a better oven.
Making things means making the most of your mistakes. There are also, of course, risks and responsibilities. Oven fires are well-contained, and pretty safe, but you can’t be too careful! Watch your fire, but also build so that an un-watched fire can’t spread to timber, grasslands, buildings, etc. Where I live, there's no fire department, and I don't have fire insurance. I have to be careful, and have tried to convey prudence and caution in what I write. However, you may want to check your plans against local fire and/or building codes and make sure that what and how you build won't compromise your insurance policies. For more comprehensive technical or safety information, you could start with titles in the Resources section.
Good building and baking to you! Please do let me know if you have questions or suggestions (or photos!) that might help to improve a future edition.