Charcoal
is made when wood is heated in the absence of air. Although charcoal
can be made using an external heat source to carbonise an airtight container
of wood (using a retort kiln), the most common way is to burn part of
the wood to generate the heat required, before restricting the airflow.
Traditionally this was achieved by adding a burning “charge”
(wood/charcoal) to the “clamp” (piled up wood) and covering
with turf to restrict the air. Since the 1920’s this process has
been modernised to employ portable metal kilns to contain the wood in
an air-controlled environment during the carbonisation into charcoal.
This process takes many hours to burn off water moisture and other chemical
elements. Combustion is then arrested by shutting out all the air to
leave a solid black residue to cool which we know as charcoal.
Generally speaking, the denser the timber, the better quality of the
charcoal produced. All UK charcoal burners use hardwood - not resinous
soft woods. Therefore the most commonly used woods for this purpose
are ash, beech, oak, chestnut and hazel.
The basic steps to making charcoal are outlined in the following pages.
