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Sustainable charcoal, crafted in the Low Barns woodland.

Kilns in full flow charcoal. Photo: Tim Davis

For more than two decades, the team at Low Barns Nature Reserve has been making sustainable, locally-sourced charcoal, turning surplus woodland timber into a low‑impact product that supports conservation work. Find out how the process works in this blog by Reserves Officer, Tim Davis.

Visitors to Low Barns Nature Reserve will probably be familiar with the sight of the charcoal kilns on the reserve. Durham Wildlife Trust has been making charcoal here since 2002.

Our woodland operations like coppicing, thinning and dealing with storm damage and diseased trees leave us with a surplus amount of timber. While it is a good idea to leave some dead and dying trees in the wood (something we actively do), there can be too much and making charcoal locally, in a sustainable manner can help with this in a positive way.

A person stands at dusk tending a small fire with a long stick beside two large metal charcoal kilns, with a tall stack of cut logs and bare trees silhouetted in the background.

Lighting the charcoal kilns. Photo: Tim Davis

The process of making charcoal is simply to heat up any organic matter to such a degree (approx. 350C) that compounds other than carbon, like lignin and tars can escape. This is called ‘carbonisation’. The ring kilns we use at Low Barns achieve this by burning about 30% of the wood. This will generate enough heat to carbonise the rest. At a determined point, when the temperature is optimal for charcoal formation, the kilns are shut down by blocking all of the air flow in and out of the kiln, effectively smothering the fire. Determining the point at which the kiln is ready to shut down is something of an alchemy rather than a science. There are some indications that can be used like the colour of the smoke, the colour of the tars and the temperature of the kiln measured by splashing water on it. But it is a long way from an exact science. The whole process usually takes around 12 to 20 hours. 

Three large metal charcoal kilns stand on grassy ground, each releasing thick white smoke, with a person inspecting one of them beside stacked logs and leafless trees.

Charcoal kilns in operation. Photo: Tim Davis

These days, the main use for charcoal is for barbequing and outdoor cooking. It also has other uses including cosmetics, blacksmithing and soil improvement for agriculture and gardening (BioChar) as well as an immerging interest in using it for carbon capture and storage.

At Durham Wildlife Trust, most charcoal is sold for use in BBQs and is available at Rainton Meadows, Low Barns and Broomhouse Farm Shop at Witton Gilbert.

The income from sales helps towards the Trust's day-to-day running costs. We are also following trends in the industry to produce BioChar (not yet commercially available) as well as supplying local blacksmiths with suitable grades of charcoal.

The open boot of a blue car packed tightly with large brown paper bags labelled “Durham Wildlife Trust Barbeque Charcoal,” with greenery visible behind the vehicle.

Charcoal out for delivery. Photo:Tim Davis

Our charcoal is locally-produced, using materials from our reserves and is sold locally, so has a surprisingly low environmental impact compared to other heating/cooking methods.

Using locally-produced charcoal has in fact 95% lower carbon footprint that imported charcoals!

To check if we have charcoal in stock, call 0191 584 3112 or visit Rainton Meadows / Low Barns visitor centres.

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