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Earth Ovens for Food & Community

What is it about the smell of fresh home baked bread and the laughter of a group of friends that brings people together and forms lasting and meaningful relationships?

 

Perhaps it’s the rekindling embers of a thousands of years old cultural tradition of sharing space, place, and community interdependence together that we don’t find often enough in our modern, so called ‘technologically advanced’ society.

 

Building an earth oven to bake local bread and share space with others in your community provides a foundation for deeper, more meaningful relationships with friends, neighbors, the community, and the land base that supports all of this.

 

With a half a dozen or more people, you can construct a simple earth oven in a weekend, and be baking within a week.

Here’s What You’ll Need for a 22.5” Oven:

1-3 tarps for mixing

1 bale of rice or wheat straw (not hay)

4 – 5gal. Buckets of fine sand to form dome

8 – 5gal. Buckets of oven mud

(H2O, clay, and sand)

8 – 5gal. Buckets of insulating mud

(H2O, clay, and straw)

16 – Hearth bricks

12 – Arch bricks (optional, but recommended)

Foundation material such as urbanite or stone

1 – 50lb. Bag of mortar for arch and foundation

Wheelbarrows, shovels and hoes can be helpful

6+ enthusiastic people, kids encouraged

7 Reasons for Using Mud by Kiko Denzer

Mud is: Fun, Fast, Art, Cheap, Community, Adaptable, Brick

Most of the info on ovens came from Kiko’s Book: Build Your Own Earth Oven

 

10 Steps to Building Community:

 

  1. Gather materials: You can find clay in your subsoil below the organic matter in your topsoil. Clay subsoil should be lighter in color and be fairly sticky when it gets wet. Mix some material and a little water and mold it into a golf ball. If it stays fairly hard when dry, you’ve got enough clay, if it crumbles; you have too much sand or silt.
  2. Lay a foundation: Urbanite (sidewalk concrete) is a great foundation material. Be sure to get pieces that are all the same thickness to make it easier to stack. With either stone or urbanite, always place a solid piece over a joint for a sturdy foundation, and use mortar (cement or cob) to hold the pieces together for more strength. You’ll want it to be about the height that is comfortable for working in the oven, and for a 22.5 inch hearth, you’ll end up with a 45” overall width. You can also mound up clay rich earth to save space but be sure there is a non-porous capillary break between the ground and your oven somewhere along the way. Give a day to dry before adding sand and mud.

  3. Lay the hearth: Use the cleanest red clay bricks you can find. The smoother the bricks, the closer they’ll fit together and the smoother the surface of the hearth for sliding pizzas and breads in and out without catching on bricks. This is also the time to lay the archway for a sturdier door and longer lasting oven if you’d like that. This is the only time you have to use mortar.

  4.  

    The Earth Oven at Baker’s Alley

    The foundation below has an open space to store firewood to dry.

     

  5. clumps well when wet. Wet the sand and lay it on the hearth as show in the figure. You’ll want the mound to be about 16” high. Moisten as needed and use and try to get as smooth and round a mound as you can. To make the sand easier to remove, cover the mound with strips of wet newspaper completely.

  6. Mix oven mud and slab it on: Mix 1 part clay soil to 1 to 3 parts coarse sand on a tarp. You may want to sift the clay soil through ½” wire mesh first if there are a lot of rocks in it. Add water a little at a time and start stomping with your bare feet until you get the consistency of homogenous creamy peanut butter. Make a baseball size blob of mix and drop it from waist high. If it crumbles, it needs more clay or more mixing. If it splats, its too wet. If it keeps its shape fairly well, it’s just right. Press handfuls of the mix around the base of the oven, over the exposed hearth bricks, holding them in place. You’ll want to maintain a strong square edge on the outside as you build up, pressing the mud against itself and not the sand form. Pack mud tight!

  7. Mix insulating mud and slab it on: Sift your clay soil to get any rocks out and pour into a bucket 1/3 filled with water. Let stand overnight and then mix to the consistency of heavy cream. Pour on to tarp and mix in straw until completely covered and a ball keeps it’s shape. Add to oven same as above. Mix an earthen finish plaster just like oven mud but sift clay finer and use beach sand for a finer texture. You can mix in clay pigments for color too. Cover insulation layer with finish plaster either by hand or trowel. Have fun!

  8. Remove sand when dry: Make take a week. Better to be safe then sorry with a collapsed oven. When completely dry inside start a small test fire.

  9. Make an insulating door: A 10x14 door can be made with a few pieces of 1-2” thick scrap wood and can be held together by a perpendicular piece that acts as a handle. Doesn’t have to be fancy, just a fairly tight fit.

  10. Invite friends, neighbors, and community over: Be sure to have at least 10-12 good pieces of hardwood. Start your fire small with softwood and build up to a larger fire in about an hour. Keep adding logs without smothering until the top of the oven becomes almost white in color.

  11. Bake bread and share with one another: Rake out the coals and ashes into a safe place (You can use them to make potash for soap). Place the oven door on and give it 30 mins for the heat to soak into the thermal layer evenly. Use a small handful of cornmeal to test the temperature – If it burns up instantly, its too hot, if it turns golden shortly after being thrown on the hearth, its just right. It’s best to start with flatbreads because they are enjoyable immediately and can take the high heat. Some like to go pizzas next. Or you could move on to sourdough, yeast breads, potatoes, beans, veggie bakes, sweet breads, pies, cookies, crackers, granola, even yogurt when the temperature drops to 100 degrees at the end of the day.

 

Here are some thoughtful considerations:

  • Check with your neighbors to make sure they’re hip to the idea
  • Always have water around to put out an unexpected fire
  • Don’t let your oven erode in the rain. Coat it with a few coats of boiled linseed oil or better yet put a roof over it.
  • Don’t waste wood. Only fire it up with lots of food to cook

Online Resources for Appropriate Technology, Ovens, Saving Water and More:

  • www.aprovecho.org - www..cd3wd.com/INDEX.HTM
  • www.solarcooking.org - www.h2ouse.org
  • www.cityrepair.org - www.journeytoforever.org