Can you make biochar with a Garn?

I remember Heaterman saying one time that if the blower on a Garn stops during a burn for whatever reason that it is a creosote making machine and makes a hell of a mess pretty fast.
I'm wondering about stopping the blower after it has burned down to nothing but a glowing orange heap of coals with barely a wisp of blue flame. I'm wondering two things: Can it make creosote at that point? and If the glowing coals are allowed to just sit there and cool off, is that good for biochar?

With my new controller it shuts down with coals still glowing.I use them to start the next fire

Don't know, but that's what I'm thinkin when I throw my "cleanings" on the snow covered garden!

Rick, when my fan shuts down I also have enough for starting the next fire 12 hours later. In the summer when I don’t fire often it seems there is still enough air movement that most of the coals are gone when I want to refire. I do not get creosote with the few coals when the fan stops. I may be wrong but I use a white loading door as an indication of a successful burn.

We had a charcoal maker at a local sawmill years ago. They fired below a tank to distill the moisture gasses out of the wood and then covered and cooled. The wood was not flaming.

Sawyer, About the charcoal maker you mentioned. I have googled making charcoal to death and have found exactly what you discribe. It's always a bottom-up process of burning the wood in the inner vessel in a low oxygen atmosphere. Real environmentally conscious guys add a stack to the top that makes an after burner set-up just like a Garn does except without the forced draft and of course the Garn burns horizontally.
I asked about the coals left in the Garn because it would be nice if I could use the heat from the gasification of the Garn to heat my domestic hot water in the summertime and stop the fire short to collect the coals to make a soil amendment (biochar)...........ps- I even talked with an older farmer that said the same process is used to make a base for black power production. He said alder is best because it is very porous.

I use the ash for my food plots and forest trails, it was recommended at a rate of 1#/100 sq/ft.

I have a friend that is a pyrotechnic, he makes his own gunpowder. He uses different species to vary the burn rate of the fireworks. He has to have a liscense and an approved safe to do this. His facility & records are regularly checked by the BATF for compliance.

Rick
I would think the Garn air intake dampner would help to make char