Primitive Technology is easily my favorite channel on YouTube. It’s fascinating to see this guy build primitive tools, pottery, shelter, and so on using only the methods and resources available to ancient people. In the above episode, he demonstrates how to make a reusable charcoal mound from mud. If you like the video, I highly recommend you help support his future work on Patreon.
Charcoal is a valuable fuel that reaches a higher temperature than the very wood it’s made from. I’ve made some before, but with supplies running low due to furnace experiments, I decided to make another large batch of charcoal in a mound. I stacked the wood into a roughly conical shape (about 1 m wide and 75 cm high) and then built a thick wall of mud around the heap (this took 6 hours). Eight air entries were made in the base of the mound and one air exit hole was left at the top of the mound to allow the volatile components of the wood to escape while creating a natural draft to keep everything burning. (read more)
Another favorite, how to make a clay kiln and all sorts of pottery from a termite mound.