I’d like to share my new style biochar making setup.
It is based on the principals of the trench burn that I played with last year very successfully. Most of my feed material is long branches - hedge trimming, prunings etc... and we get a lot of it. I don’t want to cut it down to tiny pieces for a retort style.
Anyway, the easiest way to show it is with a picture.
When using it, start fire with small dry sticks and keep on adding material until it is burning well across the whole length of the drum. Then keep on adding more fuel over an hour or so, as it burns down. The branches burn up, and the embers fall to the bottom of the drum, where oxygen can’t reach it. So long as you keep adding more fuel above the char is protected by the flames above.
When finished, I just rolled the whole drum over and shovelled soil around the edges to exclude air. 24 hours later it was cool and ready to use.
The char produced is fine and crumbly, and the drum can be placed either where you want the final char, or taken to where the fuel is. Very easy.
Moderator, Treatment Free Beekeepers group on Facebook.