Friday, September 16, 2016

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.



 #2. 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.



#3. 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.



#4. 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.



#6. 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.



#7. 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.



#8. 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.



#9. 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.



  1. Hi Kev ... great posting on the practicalities of using a Ring kiln for making charcoal ... however, do you have any precautionary tails about unintended explosions with kilnes re-ignighting themselves & resulting in the lid blowing off?

    1. Hello Don. I have never experienced the kind of disaster that you are warning of, neither do I know anyone that has. However I can see the possibility should one try to open the kiln before the fire is properly out -then fresh air mixes with Carbon Monoxide and ignites explosively. Although I understand that the first-timer would be impatient to view the results, I can't emphasise too much the need to allow the kiln to cool completely before opening. The main hazard to the collier is sudden flares of burning wood-gas towards the end of the first stage.

  2. Very interesting and well compiled article Kev. It is a shame I have no photo's of the unsealing and emptying of the kiln.

    1. Thanks, Ian. I believe the important things here are the loading (would also have been good to have more detailed pic's of the layout)and firing procedures. Emptying of the kiln is less technical, though I would have liked to have had some of the riddle converted from a redundant "Boby" seed cleaner, of which I was somewhat proud. Interesting that almost all the equipment used here was re-used / recycled from the redundant grain store,cleaner and drier.