Making Charcoal at Charlton Court Farm, Steyning, West Sussex circa 1991.
#1. The kiln was filled with seasoned wood cut and split so that no piece
was thicker than 4". The base layer is laid radially, leaving horizontal
tunnels from the eight flue-bases to the centre of the stack. The
remainer is filled concentrically leaving a vertical "shaft" right up
through the middle of the charge.
Splitting wood the old-fashioned way. This kiln held four cords of wood
(5 tons) so would take 2 or 3 days to cut and fill. The yield was a ton
(1000kg) of charcoal.
The charge is topped off with a cone of "brown-ends" -incompletely
converted wood from the previous firing- and a bucket of good charcoal
poured down the central shaft to act as kindling.
The lid is heaved over the charge and propped up on 3 wooden "chogs".
The kiln is lit by shoving a blazing oily-rag into one of the flue-bases
right to the middle of the kiln.
#5. The fire starts slowly - this is the beginning of the first "open" stage of the burn.
as the first stage proceeds, huge clouds of (mainly) steam are driven
off. When sparks can be seen all around the base falling down the inside
of the kiln body, it is time to close the lid by pulling out the
"chogs". This is the start of the second, closed phase of the burn.
The chimneys are stood on four of the flue-bases and the gap at the
bottom of the kiln body is banked-up with "grog" -a dry mixture of burnt
clay and ashes from previous firings. The join between the lid and the
kiln body is sealed with "lug sand" -a damp mixture of fine sand and
clay. The chimneys are alternated around the bases every six to eight
hours as the conversion proceeds.
As the conversion proceeds, the smoke slowly diminishes. When the smoke
turns from white to blue-ish,and the kiln-wall gets noticably hotter,
it is time to close down the kiln. The time elapsed depends on the size
of the kiln -this one took 24 hours or a little more.
The kiln is closed down by removing the chimneys and banking up the
remaining flue-bases with "grog". The kiln must then be left to cool
down for at least 36 hours, and preferably several days, The charcoal is
in such a highly reactive state that the
slightest spark remaining can cause it to burn uncontrollably if the
lid is lifted too soon. I liked to cover it with a tarpaulin and leave
it until I needed the 'coal or wanted to reload the kiln. Thanks to Chris Philps, Sean Beamish and everyone else that was involved in this project, and to Ian Mayes particularly for taking and making available these photographs.