Volume 4 Part 6
14% I intended to make soft charcoal -then
40% I'd decided to plant ... sawtooth oaks
41% hard charcoal, which could be made from sawtooth oaks
42% dependant on our attempts to make soft charcoal
So yeah, sawtooth oak does make hardwood charcoal and it is pine that makes softwood charcoal. So, either the entries at 14%, and 42%, and other references further in the story should be changed to say 'hard', or all the references to the trees shoulc be changed to 'pine'. Also, if the wood references are changed to pine, then the bag or acorns would have to change too.
Alternatively, I suppose that the next chapter could have him preparing pine trees for the actual kiln work to make the soft charcoal. The pine would have to be prepared and dried too, so that order would have its own issues.