Charcoal


The History of Charcoal

Charcoal is one of the oldest chemical processes known to man. Charcoal burning has been practised as long ago as 5,500BC, used for smelting of metals. It could achieve temperatures higher than any other fuel available at that time and was used to smelt copper and later copper and tin to produce bronze. Charcoal’s use for smelting metals grew with the iron age and continued to be a highly important product right up to the industrial revolution when coal and coke took over as more efficient fuels for the growing industries of that time. However, without charcoal the bronze age and iron age simply would not have happened.

In the Second World War, scientists discovered “activated” charcoal for gas masks could be made from nuts and fruit stones. Children were asked to collect vast quantities of conkers for the war effort, but many were left to rot at railway stations. By the 1950s, the british charcoal industry was said to be over.

Interest in traditional burning methods started again in the 1970s. By the late 1980s the charcoal industry was back on its feet, this time to produce charcoal for barbecues. Now (2004) there are approximately 300 charcoal burners in Britain. The British alone burn through over 55,000 tonnes of charcoal a year despite our lack of barbecue friendly weather! The sad fact is, that of that huge quantity less than 5% is produced here in this country. The other 95% is imported from abroad contributing to the destruction of valuable rainforests and mangrove swamps with little regard for sustainability or the effect on the local animal life.

Charcoal itself is scientifically known as amorphous carbon and it's make up is approximately 96% carbon and 4% ash. It is produced when wood is heated to a very high temperature, up to 500 degrees celsius, with a limited supply of air. This process is called carbonisation. Other bi-products produced in this process include creosote, turpentine, methanol, pitch and flammable gases. These are either given off with the smoke and steam or in the form of a tar-like substance that deposits itself on the inside of the kiln and around the chimney ports.

Producing Charcoal

Stage One: Hardwood is the best timber to use, these include ash, beech, cherry, oak and sycamore, softwood can be used but due to its weight and density a full kiln of soft wood produces a much lower weight in charcoal. Ideally the timber should be seasoned for 6 to 12 months although green can be used but the burning time takes longer.








Stage Two: Cut and split the timber to size, every charcoal burner has a different opinion what the optimum size is.

Stage Three: Firstly make a hearth in the centre of the kiln using 2 logs approximately 18” long and then place brown ends and charcoal on top which produces a charge. Next lay 8 lengths of timber in-between the ports around the kiln allowing for the flow of air while the kiln is burning. The base of the kiln now looks like the spokes of a cartwheel. Then build a raft of timber on top, working in a circular fashion starting in the middle with the thickest timber and introducing thinner timber around the outside of the kiln. The kiln can now be filled up with lengths of timber or logs. The lid of the kiln is then placed on top, held open with 4 lengths of timber to allow for steam and smoke to escape and not to suffocate the lighting of the kiln.








Stage Four: To light the kiln use an oily cloth tied onto a length of timber, this is then pushed through a port and into the hearth in the centre of the kiln. The next 40 minutes produces clouds of steam and smoke that can be seen for miles. Once the kiln is going well the 4 lengths of timber holding the lid open are removed and the lid is then sealed with sand or soil. 4x chimneys are then placed over the ports, these are changed approximately every 7 hours to stop timber burning around the port entrance in the kiln. The next 18 or so hours produces white fluffy smoke in large quantities from the chimneys, this is as the moisture is being driven out of the timber. After this time most of the moisture should have been expelled and the smoke turns to a dirty brownish colour and has a strong smell of tar. This stage of the burn is known as pyrolosis, here tar, pitch, turpentine and other chemicals locked up in the timber are given off.








Stage Five: To shut the kiln down all you do is remove the chimneys and fill the ports with soil and starve the kiln of air. After two or three days the kiln can be opened and all the charcoal removed (the dusty and dirty part!). It is then put over a grading machine to sieve out the fines, and then bagged up ready for sale.








The kiln we use is a steel ring kiln, it is 8 feet across and has 2 sections 4 feet tall, one sits on top of the other, it holds approximately 3 tonnes of timber (half of which is thrown in by my partner Mandy!). Burning times vary between 24 and 38 hours depending how dry the timber is and the weather conditions. It takes between 7 to 8 tonnes of wood to produce 1 tonne of charcoal.

Glossary of Charcoaling Terms

  • Activated Charcoal: This is used for water filtration and sewage treatment, refining chemicals and removing the colour from liquids. It is produced by heating the charcoal to 900 degrees celsius, driving off all the materials that obstructs the pores of ordinary charcoal.
  • Briquette: A mixture of brick dust and charcoal fines.
  • Brown Ends: Scorched wood that has not properly carbonised.
  • Charge: An incendiary of brown ends and charcoal to start the charcoaling process.
  • Dressing the Stack: The process of filling the kiln.
  • Fines: Charcoal dust collected from grading the barbecue charcoal which is too small to use. Can be used in plant pots to retain moisture or for deterring slugs!
  • Lumpwood Charcoal: Charcoal made from split cords of wood for use on barbecues.
  • Pit Kiln: The earliest form of charcoal production.
  • Sorting the Crop: The process of removing brown ends after the burn.
  • Wood Collier: A charcoal burner. The term often denotes an apprentice or labourer employed by the artisan “master burner”.

The Benefits of Derwent Charcoal

  • It is much easier to light than imported briquettes
  • Does not require lighter fuel
  • Gets hot quickly so you can be cooking in approximately 10 to 15 minutes
  • Timber comes from tree surgery or thinned and coppiced woodland
  • Helps to protect endangered rainforests
  • It's locally produced
  • Makes food taste terrific

Where to Purchase

We now sell charcoal direct! Please email us at derwent.charcoal@tiscali.co.uk or call 01768775288 / 07763311030 for more information or with any trade enquiries.

Website by Tim Leigh • Copyright Derwent Charcoal • 2011