Earth oven construction, part 2
Continued from an earlier entry....
We let the first layer dry a few days, and some fairly big cracks started to form. I decided to pull out the sand to give the oven more room to shrink as needed, and to help it dry out faster. I cut a smaller door than the final size, you can see the final door scored into the surface:
http://farm2.static.flickr.com/1239/1443314684_81e061fa2b.jpg?v=0 [1]
We ended up letting it dry for a couple of weeks due to rainy weather and other activities. It was covered with a tarp and opened up when the weather permitted to dry out. Next came the second layer. The first layer is just sand and clay—the second is cob: sand and clay mixed with straw.
http://farm2.static.flickr.com/1368/1443313710_f479fba985.jpg?v=0 [2]
The second layer goes on much faster, but as it's 6 inches thick you use up a lot more material as you go. We made LOTS of batches of this.
http://farm2.static.flickr.com/1260/1442449505_b5cda095e2.jpg?v=0 [3]
Almost there:
http://farm2.static.flickr.com/1182/1442450317_7efc87c836.jpg?v=0 [4]
Refining the doorway:
http://farm2.static.flickr.com/1208/1443313758_b3154e54b5.jpg?v=0 [5]
Our door, made from glued-up 4 x 4s, and shaped with a sawzall. Did I mention I have a very handy assistant?
http://farm2.static.flickr.com/1244/1442450793_11879b0dcc.jpg?v=0 [6]
We lit some small fires at this point to aid in drying, and after a couple of weeks started using it. The first few attempts had a big learning curve, and I think I joined the fresh loaf soon after that and documented my later bakes.
The oven was built in May and June, and we left it without a final protective plaster because we were undecided on what to do. We would cover it with a tarp when not in use. Finally, we decided just to make a roof over it, so there is no final plaster layer. It made it through a winter and another summer without much damage. Here’s the final oven with it’s roof:
http://farm2.static.flickr.com/1435/1443313790_6629aee699.jpg?v=0 [7]
Many thanks to Kiko Denzer for a great book--its a wonderful way to give wood-fired hearth baking a try without a huge amount of investment (well, if you don't count your time!). I also have the Bread Builders book which I found useful as well, I just didn't have the right location and finances for a masonry oven, and I think after a few years using the "mud hut" I will know better my needs and desires for any future ovens.