Hey biochar enthusiasts. I thought I'd provide a link to Primitive Technology's new video on a "Reusable charcoal mound":
This method is obviously not ideal for getting a homogenous batch of char. As you can see, there are a bunch of branches that haven't been chared all the way through. But, if you're like me and not as concerned with that sort of thing and just looking to build a biochar kiln completely free, then I would say that this is definitely worth a shot
I hope this finds someone, like me, who has been looking for a free earthen-based design for a biochar kiln.
Very few direct-burn methods would produce better results. There are always partially-converted pieces when making charcoal… and always more of them than you think there should be.
My only problem with this method is how labor-intensive it is. I understand that it's showing a very primitive technique, and that a lot of refinements can be made to cut the time and effort. For me, permaculture is about providing for my needs in a way that doesn't keep me away from my family all day. The process shown in this video is interesting from an anthropological point of view, but I have zero interest in attempting it.