Using the Kontiki to produce clean char

[Ruth Thompson]

What is best option when using the Kontiki to ensure brittle, clinking (‘metallic-sounding’) biochar;
rather than soft char (crumbly, breaks to powder in hand or when walked on).

[Admin]

hi Ruth - when you mention the metallic-sounding biochar, this reminds me of 'white charcoal' which is produced at higher temperatures than normal charcoal and for longer periods of time (several days) after which sand is heaped on to the hot charcoal to quench it. White charcoal is produced in Japan and other Asian countries where it is valued in high-end restaurants for cooking as it is very dense and keeps alight for 3 or 4 hours. It has an amazing structure when viewed with a scanning electron microscope. Is this what you are trying to produce? If so, I can dig out my notes on the method. Also, you have to use particular kinds of wood for making white charcoal, i.e. dense wood such as oak.