22 July 2008

How to Build an Earth Oven

Do you remember your teachers asking you on the first week of school what you did for your summer vacation? Well, if I were still in school, this would have been a story to amaze my teacher and classmates.
My friend, TH, is an amazing baker and cook. She is also very wise in the ways of crafts and organizing activities that bring diverse people together.

Her great ambition has been to build and use a wood-fired oven in her own backyard. TH is not someone who merely dreams big -- she builds! She did her homework and found a book by Kiko Denzer called Build Your Own Earth Oven. She also found a website showing a group of masons who built an oven of the type she wanted using Kiko Denzer's model. Here is another website I found of a group of Australian gardeners built a similar oven.
Then she and her dad cooked up a scheme to build a test model in his backyard as a practice version. Her two teenage sons helped their grandad build the test oven. This was very wise since they notice a water-seepage problem because the test oven had no drain. So, they knew they had to make drainage holes in TH's oven.
TH's Dad drew plans up for brick foundations to be built in her backyard over the course of several summer weeks with the help of his grandsons. Then, the next step was to create the inner oven wall, made entirely of cobb, that is, clay from a local source, plus sand, mixed with straw.
And that's where I come into the "Earth Oven Project 2008," because TH invited me and a group of her friends and neighbors to be a part of the oven's creation.
It was an extremely hot (mid 90s F) day in mid-July, but not so humid as Maryland suburbs can be in this season. When I arrived on the scene, the boys were mixing cobb, as the English settlers to North America called it. Cobb is the blend of clay, sand, and straw that forms the bricks to create the earth oven. Here's an image of the boys pounding it out by foot and testing its moisture content.


While the boys were mixing cobb, it was up to the rest of us to prepare the igloo-shaped sand mound around which the inner oven insulation would be formed.








After we made the sand mound (notice the brace we used to prevent sand from rolling off the edge), we covered the sand with wet newspaper, rather like you would a form for papier maché. By the time all hands had covered the sand mound with newspaper, TH's husband G had laid out a delicious spread for a hardy lunch. I had brought the beer and cider and there were copious amounts of herbal infusions and lemonade available for thirsty workers.
The next phase was to cover the entire sand mound with cobb bricks, so we spent the remainder of the afternoon doing just that. A shady yard and a bit of breeze go a long way to making summer's heat bearable. So does telling stories, laughter, and watching the boys rough-housing. We generally had a merry time at it, despite the heat.









Finally, about 5:00 p.m. we neared the home stretch. Only a tiny hole a the top of the insulation layer remained.
It takes something very interesting indeed to get me out on a 90-degree day, but this project was well worth it. I can remember with fondness mushing mudpies in my hands, but this is the most ambitious "mudpie" experiment I have witnessed. It's also very like molding a clay pot on a grand scale. The end result is larger than any typical potter might attempt on her/his own. The very social aspect of building something like the earth oven as part of a group, including several families, several generations is not unlike our pioneer ancestors did when a house frame or community barn needed to be built.
The outer layer of insulation and the final brick housing for TH's oven will be constructed by her, her family and friends next weekend.
I look forward to coming over to her house someday soon to enjoy wood-fired bread or pizza baked in her backyard.

PS. if you wish to know more about this fabulous earth oven, please contact my friend who runs Dances with Loaves in Maryland.

20 comments:

  1. Wow, Maria that's awesome! I don't know if I would have the patience, but it sure sounds like a fantastic collaborative effort. :)

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  2. We dug out the sand today and built the first drying fire. There are some cracks developing, which we will repair tomorrow. So far, we have not seen any condensation draining out of the holes we left in the mortar. But then, we were much more careful to use as little water as possible on this oven! The biggest problem now is that the oven needs to be out in the fresh air drying out, and we have to keep running out and covering it up with the tarp every time another little rain squall blows through!

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  3. T,

    I forgot to add that your people call you "Dances with Loaves!" *grin*

    I'm so glad the oven has passed it's first test.

    Hugs from,
    ~runningwave~

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  4. We finished the oven today. IN a few weeks, the oven will have a small gazebo over it to protect it from rain. My father has done the shop drawings and will wait to cut the wood until my oldest son is able to spend a few days with him to work on the cutting together.

    Yesterday a friend and her four-year-old came to help with the oven. We experimented and found that two parts perlite, one part finely chopped straw, 1/4 part dry sifted clay and one part slip made a light mix that would pack and hold a rough shape on its own. working with it, we built the oven's outer cob wall a few inches high, then packed in the insulation. Today with a larger work party, we covered the entire oven with insulation and an outer wall. Now we begin really drying the oven with daily or almost-daily small fires.

    My nephew has just returned from a 60-day research trip to Jersey where he has been working with the L’Office du Jèrriais at Highlands College near St. Hillier. Showing off his newly-acquired ancient language skills, he inscribed "Lé fon du pain" over the door. So now it's official - the bread hearth.

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  5. Yay! The oven construction is complete. That's great. I think your nephew's unique contribution is highly appropriate. I will be happy to come and visit your hearth sometime soon.

    Hugs,
    ~runningwave~

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  6. My husband and I have dreamed of doing this. We live in Annapolis. We would love the chance to see this project before we take the leap ourselves - if your friend would consider this?
    Thank you,
    Sandra
    swhite828 at netscape dot net

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  7. Sandra, I've contacted my friend to let her know you are interested. She has had success with her oven and now runs a bread-baking business called Dances With Loaves.

    http://www.danceswithloaves.biz/

    Peace,
    Runningwave

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  8. Are you going to be there to document the remainder of the project? It's not even half done at this stage.

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  9. I would very much like to see a pic of your end project

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  10. Triple ditto on project documentation and end project pic --- I'd do one in a heart beat if it worked for you ---

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  11. Thanks for the comments on my photos. I can't take credit for this oven project. I only worked on one day of the construction.
    The whole thong was/is a labor of love build by my friend Tish and her family. You can see a picture of her completed oven and get into touch with her via her home bakery business website, Dances with Loaves (coolest name for a bakery, imho): http://danceswithloaves.biz/1852.html

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  12. Here is my favorite earthen oven.,,
    http://arcadianclock.com/dru/Munro_Tower/Oven/

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  13. More folk should just make one. If it does not work it is just mud.
    Cobb is a good thing because the wholes left by the straw help insulate.

    It is also possible to mix cement and dirt.... Plaster with a thin layer of stucco and white wash... Just be sure to dry it as slow as you can. White wash looks nice but black gather heat from the sun.

    The inside need not be circular, egg shapes work.
    Chicken wire or hardware cloth can add strength.

    Do measure the entrance if nothing else. Make sure you can slide in a 9" steel pie pan. You can build a charcoal fire on the pan and slide it to the back.

    Hard brick around the inside will endure thump and bumps in use. Consider
    a hole low on one side to allow an iron pipe to let in propane or natural gas. You can plug it if you do not want it...

    Hardwood like oak can burn hotter than coal. A black iron rectangular griddle can be used as a door if you find one in a flea market.

    Lots of folk only cook pizza or bread, brazed beef or pork can cook in the
    latent heat for hours.

    Do keep clear of anything that might burn.
    Do enjoy.

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  14. This looks like a great project!

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  15. here is our several year old version of one of these pics show it in use..

    https://www.facebook.com/media/set/?set=a.114769225283780.22833.100002521099608&type=3

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  16. Using a brick oven is very important to bakers since the bread tastes better when cooked with wood. It’s already been four years after this post and I hope the oven is still working. I also using a brick oven whenever I try to experiment with different pizza toppings, and I love the way it cooks my delicacies. It makes it more special. By the way, the brick oven she made was beautiful! :D

    -Nohemi Tutterrow-

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  17. where I get the clay?

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  18. I smell pizza


    Have you tested tempatures? On the bottom and in the dome?

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  19. Thank you for your comment, but this oven was the brainchild of a dear friend of mine. She runs Dances With Loaves bakery, and you will need to message her regarding the temperatures and details of construction. I was just the hired help for the day. ;-)

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