Joel Meadows talks through his charcoal retort oven

Alt-tech workshops team member Joel Meadows has just completed this amazing piece of alt-tech wizardry – allowing him to simultaneously create top-notch charcoal for his forge and cook dinner at the same time! Then, after dinner, he can go make another knife or something in his charcoal-powered forge (which in turn he can use to slice tomorrow’s pizza).


  1. Great to see more people using the heat generated when making charcoal for another function! real permaculture!

    If the oven were higher could the char burner be underneath with a very short straight flue under it? or is there a specific reason for the flues to be ‘long and bendy’?

  2. Uhm, Joel.

    That oven is made of galvanized steel, correct?

    Now, I don’t KNOW how hot galvanized steel has to get before the Zinc Oxide starts to fume into the air.

    You can get Zinc poisoning just from sanding the metal.

    So… Joel, be careful, okay?

    You could be exposing your food to zinc fumes.

    Play it safe. Make a new oven from a stainless steel barrel.

    • Dan Palmer

      July 24, 2016 at 4:42 am

      Hey William no need to worry – as Tim Barker explains: “No.The outer skin is Gal but it is separated from the flame by a layer of mild steel and then nearly 50mm of rockwool insulation so you can lay your hand on it. The food is cooked in a non coated mild steel container so totally separate. Gal has to get up to approx 900deg c to begin to vaporise and it will then only cause probs if you specifically inhale the vapor. Its called Zinc fever amongst other things and as a welder i have got it a time or two over the years when welding Gal. Joel will know this too but my two cents worth. Also if you get it to those temps it will then oxidise and you could cook in a black oven using a gal heat riser after the gal is all oxidised.
      Cheers Tim”

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