Cob Ovens for Outdoor Eco Cooking

Have you ever fancied making a pizza or baking bread in your garden? A cob oven is a simple to build, highly efficient oven which you can build in your garden from material you probably already have in your yard. And it makes the best pizza and bread you’ve ever had.

Cob ovens are beehive shaped domes made from mud bricks and sand. They’re incredibly easy to build and make a great project for the garden. It involves getting your feet and hands muddy so kids will enjoy it too.

First, get your basic ingredients together. You’ll need sand, clay (if your garden has a clay soil use this) straw, some building bricks or breeze blocks, and some fire bricks.

Here’s a two-in-one cob oven and rocket stove, designed and built by Larry Santoyo, Permaculture teacher and founder of Earth Flow Design Works

Next, build a foundation or base for the oven t osit on. It should be at around waist height, so you’re not crouching on your knees to put food in the oven. You can use breeze blocks or old building brick to reach your required height. Imagine a wishing well – it should look like this.

Cover the top of the base with a layer of sand, then lay some fire bricks on top. This is the base of the oven, and food will cook on this.

To build the dome (which will become the oven’s interior), pile a load of damp sand onto the base, and form it into a dome shape.

Now it’s the messy and fun part. You’ll need to make the cob – these are bricks of sand, clay and straw. Mix them together as 75% sand with 25% clay. Form two batches, and add straw to the second batch[1]. The best way to mix it is by putting the materials on a tarpaulin and treading it all together with your feet.

Now to create the dome. Take the cob without straw and layer it over the sand dome. Builds it up to at least 4” thickness. Then apply the cob with straw over the first layer, again at around 4” thick.

OK, you’ve now got a cob dome, full of sand. What next? You’ll need to cut a door and this should be 60% of the height of the dome. This height is critical[2], as it allows the oven to draw (suck in air) and pass smoke out – the oven has no chimney.

Scoop the sand out once the cob is dry, and the dome should be self-supporting. Allow it time to dry out, and your oven is now ready to use. -MARK LEE

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