Charcoal and Biochar in the Highlands

Well after decades of wanting to make charcoal, I finally did it! woo hoo!

For so long I have been yearning for a ring kiln to make it in.  Thankfully I waited so long…… that somebody else invented an even better way of doing it.  Bonus!

I introduce the Biochar Retort Kiln, it’s a beast! All I ask is that you bow before it!


The beauty of the retort kiln is in it’s greatly more efficient process.  It harnesses the volatile gases given off from the wood being turned in to charcoal and re-enters them into the fire box, igniting them and eventually fuelling the kiln for the rest of the burn.

After much research on what was out there, I enquired with some well established biochar retort people who, could make me one on a trailer, for a mere £17-£20,000, so that was the end of that.  But they were kind enough to point me in the direction of James Hookway, who sold me some plans for his Hookway Biochar retort kiln for a pleasant £10. Result!

Bought myself a rather pleasing empty 45 gallon pineapple juice drum with a resealable lid from eBay for 27 buck delivered, found some 3mm thick x 5 1/2″ steel pipe on gumtree from a weather monitoring company who made masts with it, I got like nearly 5 metres of it for £30, absolute bargain. I also found a bit of old scaff bar in the shed and I was set. charcoal making here we go!!

So I chopped and welded away, I tell ya, trying to figure out 45 degree bends on round pipe is a total headache, I would be sorely tempted to make it from box section steel next time.

And voila! I made a kiln, sweeeeet!  So your supposed to insulate and well, I didn’t have any, so I gave it a blast and although It didn’t entirely work as it should, I did make charcoal, not premium grade yet but nonetheless it was charcoal.  So I realised after, there was an amendment to the plans on a separate file which I totally forgot about, which meant changing everything about, chopping bits off and re-welding, but hey ho, not the end of the world and I did it and fired it up, still with no insulation, and , it didn’t really work. Bummer.

So figured I would have to shell out for some knauf earth wool insulation, which is supposed to be super duper fireproof, and kind of is, unless you put it on the top, but to be fair, it must reach in excess of 700 degree’s C.  So some modifications to be done there.

Anyhoo, I moved it into my bothy as the midgies were horrendous as ever and the weather was mingin, made a couple of flue elbows from some veg oil cans to put the flue outside, had my newly attached earth wool insulation and fired it up.

She’s a Beast!!!!!!!

The power that comes off this when it’s really retorting(gases igniting) is quite humbling! It is literally like a jet engine!  Stood there giggling to myself!!

Biochar Retort Gas Burn YouTube video

5 hours later, job done, leave it till the next day to cool off(very important) and hey presto I had some awesome charcoal, you can supposedly tell the quality of the charcoal, if it sounds a bit like glass…ish when you drop it on the rest of the charcoal..? Mine did, so thats great!


So fast forward a year and Im still tinkering away with improving the design…. There is so much to share that I will create a blog for this me thinks…..

I will also hopefully explain to you the importance of what Im up to with this and its very poignant real world application….


stay tuned!