This article deals about the production of charcoal.
Methods
Charcoal has been made by various methods.
Using a clamp
The traditional method in Britain used a clamp. This is essentially a pile of wooden logs (e.g. seasoned oak) leaning against a chimney (logs are placed in a circle). The chimney consists of 4 wooden stakes held up by some rope. The logs are completely covered with soil & straw allowing no air to enter. It has to be lit by introducing some burning fuel into the chimney; the logs burn very slowly (cold fire) and transform into charcoal in a period of 5 days burning. If the soil covering gets torn (cracked) due to the fire, additional soil is placed on the cracks. Once the burn is complete, the chimney is plugged to prevent air to enter.[3] Modern methods use a sealed metal container, as this does not have to be watched lest fire break through the covering.
Using charcoal kilns
Several (relatively inexpensive) charcoal kilns can be made which can be used to make charcoal/ See the designs at Biochar-international page 1 and page 2 Most of these require atleast some parts which can not be found in a natural environment (ie metal parts). On the upside however, such parts typically last longer and may be more efficient. Some very simple designs also exist consisting of only a few metal parts (ie 2 barrels), see NASA Langley Research Center's low-tech kiln