Dear Oven builders, mud teachers, bakers, and eaters: I would like to talk to you about some of the claims being published about the efficiency of earthen ovens. I think we need to be clear that any masonry oven, whether it's made of unfired earth or fired brick, is not, by definition, a "fuel efficient appliance" --Â especially if it isn't insulated. There are more and less efficient ways to work with an oven, and some of them make quite good use of the wood burnt in them, but in my experience, those ways don't apply to people who just want to cook a few pizzas, or a few loaves of . . .