Is the intent to char the bones without the volatiles escaping? And condensing the vaporized bone volatiles in the water? Similar to wood vinegar? Do you try and avoid the fire from heating up the water?
Discussion
Yeah and it ends being quite thick and fatty from the marrow so it helps trap the volatiles that way too...so you don't want to make it with old bones.
Ok. So cut the bones to let the marrow out or do they come out during charging? Can you use bones that were previously used for broth?
Good question the ones I have were cut but I would assume it would leach out anyway. I guess you could use the ones already used for broth though I guess you would have slightly less nutrient in it if you wanted to use it for wcap later. Butchers will give them for free and cut anyway so if you are going there just ask them to give you some.