I began with trying to do it by the "direct" method, in a 40-gallon oil drum, filled with sticks, fired up, air excluded. I had about 4 tries, all pretty unsuccessful. Even starting the fire was problematic, but a fire lighter eventually sorted that out. But it was difficult to get the right balance between either charred brown wood or too much burned to ash.
Then I read about the biscuit tin method. Beautiful.
This is the biscuit tin on the fire. Note the flames coming out of the stab holes. Sometimes there is a safisfying "whoomp" as the gas explodes gently.
Here's what you do:
- Get a biscuit tin.
- Eat all the biscuits.
- Stab holes in top.
- Put sticks in tin.
- Put tin on domestic wood fire when you go to bed.
- In morning, open tin, put charcoal on a pestle and mortar and pound it to dust.
- Put charcoal dust on garden and dig in.
Next morning. Finished product.
The idea is to make Terra Preta, the highly fertile charcoal rich soil found in South America and elsewhere.
I'm putting the charcoal onto one patch, and will compare productivity of that patch with another, non-charcoal patch. I'll let you know how I get on.
Apart from the hoped-for fertility advantage, the carbon just stays there in the soil for hundreds of years, out of the atmosphere.
Another advantage is that it adds value to the sticks that cover my land.
Townies say we live "out in the sticks". This is true.
We have a lot of sticks out here.
I smile to myself when I see bags of "firelighter" sticks for sale £4 a net in the garages.
I do not have bonfires, don't agree with them, waste of resources, polluting, and creates CO2.
So I have loads of stick piles, and many sticks escape from the piles and lie around in the grass.
So I round them up and pop them in the biscuit tins.
It all fits together beautifully, out in the real world.