How do I produce biochar?

The production of biochar is simple. However, there are a few things you should be aware of.

Here is our step by step guide

1. Ecological biomass

Here you select what is to be burned. We recommend especially old branches, for example of fruit trees. Usually some wood is produced when the trees are cut. This wood does not have to be thrown away, but can easily be used to produce biochar. It is important that the biomass is dry before starting the process.

Zerkleinertes Holz liegt am Rande einer Streuobstwiese
Old branches Photo: Naturefund
Photo: Naturefund

2. Lighting

With a few small branches and paper can be fired in a heat-resistant container. We use the kiln here. More information about the container and its use can be found here.

It is also possible to use ecological lighters if lighting them proves to be difficult.

Kleine Äste liegen am Grunde eines trichterförmigen Kilns zur Herstellung von Pflanzenkohle
Branches and paper for lighting Photo: Naturefund
Photo: Naturefund

3. Filling with biomass

After the correct firing, biomass can now be added step by step. Start slowly and add new wood again and again. Then you should wait until a slightly white ash layer forms. Only then can biomass be added again.

Bereits leicht verkohlte Äste liegen in Kiln zur Herstellung von Pflanzenkohle
Light ash layer Photo: Naturefund
Photo: Naturefund

4. Wet surroundings

Depending on the surface on which the kiln (container) is placed, it is advantageous to keep the surroundings wet with the help of a watering can. If the kiln is very full, it can happen that burnt pieces of wood fall onto the lawn. It is very helpful to moisten the ground.

Person gießt Boden rund um einen Kiln mit Wasser, um einen Brand zu verhindern
Photo: Naturefund
Photo: Naturefund

5. Burn

Keep adding biomass after each layer. It is very important to always let enough burn down.

Äste werden im Kiln zu Pflanzenkohle verarbeitet
Photo: Naturefund
Photo: Naturefund

6. Full Kiln

This is what it looks like when the kiln is now fully filled. Now you can wait again until the biomass is burned and biochar is produced.

Kiln zur Herstellung von Pflanzenkohle steht auf einer Streuobstwiese und ist bis zum Rand voll mit Ästen
Photo: Naturefund
Photo: Naturefund

7. Extinguish

With plenty of water, the fire can now be extinguished when all the biomass has been burned. Watering cans or buckets are very helpful here. This process is very important, because otherwise you don't produce biochar, but useless ashes.

Photo: Naturefund

8. Collect leachate

The leachate can be easily collected, depending on how the tank is constructed. It can then be used to water plants.

Sickerwasser wird aus einem Kiln zur Herstellung von Pflanzenkohle aufgefangen
Photo: Naturefund
Photo: Naturefund

9. Let cool down

The freshly produced biochar should then cool down well before it can be used again.

Kiln ist bis zum Rand gefüllt mit frisch hergestellter Pflanzenkohle
Photo: Naturefund
Photo: Naturefund

What happens afterwards?

The next steps

After the newly extracted biochar has cooled down, it can be used as a soil conditioner. However, it should be "activated" before that. Composting or fermentation can be used to activate the biochar. More on this soon on our page.

Go to the Studies

Protect Nature

Support our projects and protect habitats in Germany and around the world.