You will need
 

• An old oil drum or metal dustbin.
   
• Three or four bricks
   
• Something to use as a lid.
   

How to build it

1. If you are using a drum, one end needs to be removed. If the top has not been removed, cut the top out using a chisel or an angle grinder.
2. Cut some holes in the base of the drum or bin. About a dozen openings of an inch or two should be fine.
3. Place the drum or bin, with its open end up, on bricks to enable air to flow through the holes you have cut in the base.
4. You will need a lid - perhaps a metal dustbin lid or something similar.

How you use it

1. Start a fire in a bottom of the kiln using paper, cardboard and larger kindling.
2. Once you have a strong fire, load your branch wood randomly into the kiln leaving air gaps.
3. When the fire is burning really well, restrict the air intake by banking earth around the base but leave a small (4 inch) gap. Place the lid partially on so that smoke can still excape.
4. Thick white steamy smoke is created during the charring process. Bang or shake the kiln to settle the contents and create more smoke when the process seems to have slowed.
5. When the smoke changes to thin blue smoke the water has been driven off and the charcoal is burning. Close off all the air intakes at the base with more earth and close the lid fully. Make it as air tight as possible.
6. The burn will continue for three to four hours and should then be left to cool for another 24 hours before the kiln is tipped over and emptied of the charcoal you have produced.