Adobe Bake Ovens

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Noche on 8 Feb 2007 at 08:18

I am trying to get my act together and build an oven by dry stacking cement block up to waist height, fill the block perimeter with dirt, cap it with flat rock and then cover a damp sand model of my interior oven size with a first layer of good clay perhaps fire brick quality clay and then an insulating thicker layer of cob with straw in it .

I have called BLM or Bu. of Land Management to try and locate a clay pit close to me and I see on their internet site that BLM has a fire brick quality site up by Moscow, Idaho which is doable by a days trip in a truck one way. I would like to get my son involved because I think he would really enjoy the whole circle of building, proofing and baking. He worked in Sun Valley for years skiing and making pizzas. I think he could earn a nice hobby income in the Sun Valley area alone if having your own oven ever caught on in that kinky neighborhood. I worked for several years for a mason that did fireplaces up there and they would think nothing of telling you exactly what they wanted and when you built it they would change their minds and tear it out and do it over. The building was $30,000 and the tear out and rebuild was more.

Are any of you heading in this direction and what problems do you face where you live?

Charmaine Taylor's http://www.dirtcheapbuilder.com/heatmasstovo.html is great for all this kind of work.

My wife's blog covered the construction of our cob oven very well, http://thesilverwheel.blogspot.com/2006_07_01_archive.html  and it is similarly constructed like yours. For the first layer any clay is great, but for the ultimate you could use grog (crushed fire brick) like Maya at Wildfire food

Thanks for the pictures. What a great project. How does it bake and would you change anything? Are you going to build a shed over it? Have you seen any of the old French ovens in your neighborhood. It was interesting that they were brought over from France in the 1700 and then the idea died out in France and the Canadian examples are all that are left in the world. Your children are so cute.

I really like the barn in the background. I need one so badly.

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sadears on 9 Feb 2007 at 14:25

Is it outside?  How do you heat it?

 

Steph

Keeping a small fire off to one side is necessary for doing flatbreads and pizza's, to maintain a nice high temperature like 500 to 600 F. Here is an interesting company in Vermont that makes only flatbread pizzas in earth ovens, looks like a fun and tasty experience!
Ah yes, they are wonderful. It's a chain now and there are two related companies that work with the same concept. One is American Flatbread. The other, I think, is just "Flatbread." They have little mud ovens in each restaurant. It's a crunchy place. Everything organic, nitrate free, free range, etc. The flour is organic with restored germ. Tastes heavenly.
There is a book by Kiko Denzer that comes from the `crunchy` side of oven building using sand as a form and cob for the oven walls. Very complete and easy to follow instuctions and pics. Ours came out great. I still have to cast a couple of doors then it's ready for baking. He recomends a firing door with openings for air in, smoke out and a baking door with a tight seal. The book shows quite a few types of oven designs. I chose the French/Canadian down draft style for it's lower wood use. Kiko says the firing door contrbutes to the efficency. He also recomends faggots as fuel. I have an image of these bundles of wood from movies but have no experience with them. Anyone use these in firing their ovens? I've posted a few pics of ours in the gallery. We added vermiculite below the hearth and to the cob mix on the outer layers. Ron

Pumpkinpapa,

 

Thanks for the link.  It answers a question that I had posed earlier about using soapstone.  If/when the Pampered Chef baking stone that I'm presently using gives up the ghost, I'll look for a slab of soapstone to replace it.

 

Paul

I was thinking about the sand as a form.  Sounds easy to remove but it might be good to put a layer of paper between sand and clay mixture so that any sticking sand doesn't fall down on on your bread during the life of the oven.  Any sticking paper can be burnt out.  I would also be tempted to cover the sand with plastic unless you want the clay to take forever to dry.   Making a wood form is also easy to remove so long as you stand it on little wedges for feet and use weak nails to hold it together.    Mini Oven

I was thinking of the same thing and after a few ovens Denzer even suggests it in his book.

 

I have been "burned" with my thermal floor by not putting down a reflective layer under

the floor so I didn't want to go to all the effort of building an oven and make the same

mistake. So, looking around I found http://www.radiantbarrier.com/radiantfloor.htm which

has a temp shield product that I have requested material on. I think just an aluminum

layer would help. I have attempted grinding my own main mirror for a reflective telescope and

was intrieged with  the fornobravo site and their commercial ovens and comments about wall

thickness and no cool spots. I am looking at a 16" circle (steam retention for a good crust)

with a 32" footprint which is larger than I originally wanted. I may be going to North Idaho

to a natural clay outcrop where I can buy a pickup truck load of clay and experiment. 

The site looks more like something for floor heating under indoor house floors. I was thinking something more like clay mixed with straw spread thick over the flat rock, with proper Fire clay tiles on top or whatever you like to use to bake bread on.  Create a "floating floor" so that it can expand with the heat and make it thick enough to retain the heat.  A layer of glass wool or insulation might be a good idea between dirt and the flat rock.  (My father once melted an aluminum grill getting it too hot, it was cool watching it happen.)  To test for hot spots, try dusting a hot oven floor with flour and wait a minute or so for it to turn brown.  To keep the heat in after heating up the oven and the fire is out, cover the chimney with something.I know there are lots of tips out there, let us know how your experiments go. :)  Mini Oven

They are good to temps of 180 plus or minus 10 degrees, so ... they are out. The site I really like ($2,400 gulp) is fornobravo from Italy. They buy from the best manufacturers in Italy and have an interesting site that I will only use if I strike out.

Mini Oven I like your flour test patern idea for heat distribution. What have you found in rectangular ovens? Do round ovens produce even temps, rectangular uneven?

 

Thanks for reminding me that there is a section on building ovens in my book. I read the front part so much I forgot the back half. LOL

The floating floor is covered very nicely and I have some leftover rebar from building my house. It is half inch though and that looks a tad small for all that weight. I will have to check on the Diameter they used.

There are so many things to keep in mind. The cast iron door is out. I will use wood and metal. We have a metal shop at the lumber company that I buy from and they can make the dangdest stuff for you if you go in and tell them what you need. I will either do a chimney or put a metal baffel to keep the black hot gasses off my front lip. I hate to see the smoke on a nice oven.