Wood-fired Oven

What little kid doesn’t want to pile up sand on top of some bricks, cover it with clay, dig the sand out, light a FIRE inside, and make delicious pizza? I believe we are never too grown up to sit in the sandbox and play with mud! After having a blast at Stu Silverstein’s earth oven workshop at the Kneading Conference, I set out to make my own backyard pizza oven.

Using mostly local materials (100% local is possible if you have a good source of clay nearby), and some help from my friends, the oven took shape in just a few days. The foundation is made from wood so I can pick up and move the oven someday. Pine 6×6″ timbers, half-lapped at the corners make up the platform. On top of that, cement board, and then two inches of concrete with some recycled wire fence in it. The next layer is another two inches of portland cement mixed with vermiculite to create a insulation layer. Then comes the firebrick hearth, about three feet across and set into the vermiculite just as it starts to dry.

Many hands make light work, mixing the clay / sand mixture for the walls. I used dry fire clay (#40 Hawthorn) from a local pottery store because it mixes quickly with the sand and I didn’t have a ready source of clay on my property. Wetting down the sand till it is sandcastle consistancy makes for easy shaping of the mold. I covered the sand with wet newspaper before starting with the clay so that I can easily differentiate between the layers when digging the sand out. The clay is about four inches thick and forms up to and around the red brick arch opening.

As soon as the clay dome is finished, the sand can come out and a small fire started. Although it takes a few weeks of occasional firing to get the whole oven dry, pizza can happen right away! I have yet to add a second layer of clay to the oven, perhaps another four inches of clay, sand and insulating material such as sawdust or straw. So far the oven has cracked in a few places, nothing another layer won’t cover, and has been making delicious pizza and bread since day one. If I were to change one thing it would be to extend the arched opening further from the oven and make a small chimney about half way to the front. Without the chimney, it is hard to lean in to tend the fire without a few scorched eyebrows from the heat. My infrared thermometer has measured upwards of 750 degrees on the hearth once a fire has been going for thirty minutes or so!