Building an Earthen Oven in Tanzania

In 2019 I spent three months volunteering with ICS in rural Tanzania, providing entrepreneurial education and funding to a group of villagers. During this time the families who volunteered to host my team generously cooked for us every night, and I wanted to return the favour by making them some food from the UK.

However, I quickly realised that a lot of UK food assumes access to an oven, which no one in the village had. Fortunately, around this time i came across the concept of earthen ovens and saw how simply they could be made from local materials, and decided to try building one myself.

Sourcing the Clay and Sand

The first step was sourcing materials. My friend and I found sand on the bank of a nearby river and a deposit of clay-rich soil close to our house. We borrowed some shovels and a bucket, then dug up the material and carried it back to our chosen construction site.

Setting Out the Base

We started by arranging old bricks into a rough base and cooking floor. The layout did not need to be perfect, but it did need to give the oven a stable footprint and enough depth for the dome and doorway.

Forming the Internal Dome

Once the base was ready, we shaped the internal dome from damp sand. This acted as temporary formwork, giving us a solid shape to build over while preserving the oven cavity we would later hollow out.

A damp sand dome built on the brick base to form the oven interior

Layering the Clay

Next, I mixed the clay-rich soil with sand to create a workable cob-like building mix. The sand helped stop the clay from cracking too much as it dried, while the clay gave the oven its structure and ability to hold heat. Getting the ratio right was mostly practical: add water, tread and fold the mix together, then adjust it until it felt strong enough to shape without slumping.

With the sand form in place, we packed several layers of the clay and sand mixture over the dome by hand until the walls were thick enough to store heat from the fire. We smoothed and compressed each layer so there were no weak gaps, then marked out the doorway before leaving the shell to dry gradually.

The first clay and sand layer smoothed over the oven dome with a doorway marked out

The hardened clay shell drying on top of the brick oven base

Hollowing the Oven

After the clay had hardened enough, we carved out the doorway and removed the sand from inside. We had to be careful here as the dome started to stand under its own weight, but thankfully it was surprisingly strong.

The oven doorway opened while the internal sand form is being removed

Fitting the Door

Making a tight-fitting door for the oven proved difficult with our basic hand tools. Luckily, I came across a local carpenter who agreed to make one for us. The door ended up fitting perfectly, which was important for ensuring the oven would actually hold residual heat for cooking.

The finished earthen oven with a small wooden door fitted into the opening

First Firing

The most satisfying part was firing it for the first time. A small wood fire slowly hardened the inside and drove out moisture before the oven could be used properly. Some local children were very excited to help us stoke the flame.

The first small fire being tended inside the earthen oven

The darkened interior of the earthen oven after its first firing

Baking

After the oven was fired, we finally got to try it out. To use it, we lit a fire inside until it got up to temperature, then removed the coals, placed the food inside, quickly sealed the door, and waited. Using this method, we cooked bread, pizza, and shortbread, all of which our hosts found delicious.

Loaves of bread baked in the finished earthen oven

Reflection

I’m very proud of my oven in Tanzania because it brought volunteers and locals together to create something modest but valuable. We also got to share european food with Tanzanians who had never tried it before. Last I heard, many locals were interested in building their own once they saw what was possible, and the original oven is still standing there today.