Making Biochar on the Cheap

I decided to write this article because I was getting a lot of interest and questions regarding my biochar experiments on nostr.

Biochar has many amazing properties that bring many benefits to your homestead. This article isn’t about all the good things biochar can do for you, there are plenty of those already on the net. Rather this article is about how you can make your own biochar on your property for very little out of pocket expenses.

More accurately this article is about how I have made biochar on my own.

Resources I highly recommend watching before making your first batch of biochar.

Youtube – Biochar. Best method for producing charcoal for biochar.

Youtube Playlist – Biochar Workshop: What, Why and How?

Youtube – Top Reason Why Biochar Doesn’t Increase Crop Yields & 5 Ways to Fix it

Method #1 – The Conical Hole in the Ground.

For this method all you need is a shovel. I learned about this by watching the video Youtube – Biochar. Best method for producing charcoal for biochar.

Dig a hole in the shape of a cone.

Separate your wood into piles based on thickness, small (kindling), medium, large.

Build a fire in the hole with your kindling wood. As the kindling burns place medium sized wood on top of the burning kindling. Lay the wood horizontally. As it starts to burn lay larger pieces.

As the wood burns carefully smash the fire down with your shovel. This effectively smothers the wood below due to lack of oxygen (O2). This lack of O2 coupled with the high heat of the burning wood above initiates pyrolysis turning the wood into biochar.

When you bash the pile down the fire will start to die, revitalize it by adding more kindling, then medium sized wood then large and repeat the bashing process. do this until your hole is completely filled.

Once you are happy with your results quickly douse the fire with water. Dousing has the effect of shattering the biochar into smaller fragments creating more surface area for all the good critters to thrive.

Method #2 – The 55 Gallon Drum Biochar Retort

I learned this method by watching Youtube Playlist – Biochar Workshop: What, Why and How? and trying to recreate what I saw in the video.

For this method you will need:

  • 55 gallon drum with a lid
  • 4 – 6 inch diameter Stove pipe at least 24 inches long
  • A coupling to attach pipe to lid (I don’t know what they’re called)
  • Angle grinder with cut off disc or something that will cut metal
  • Drill with metal bits
  • Sheet metal screws

Important: None of these measurements are critical, this is just what I did. There’s room for improvement.

The Barrel

Drill 8 1/2″ holes 3″ from the top of the barrel

Drill 8 1/4″ holes below every other 1/2″ hole and 8 1/8″ hole above (see pic)

Cut 4 2-3″ equilateral(ish) triangular holes with angle grinder 1/2″ from the bottom of the barrel.

Cut the appropriate sized hole in the lid for your coupling

Affix your coupling to the lid with sheet metal screws.

Affix your chimney to the coupling.

The Retort – 35 gallon drum

In my case I couldn’t find a 35 gallon drum for my retort so I’m using a small garbage can with a lid.

Drill 5 1/2″ holes in the bottom of your retort (see pic)

Fill your retort with sticks and twigs and stuff. Make sure there’s a variety in the size of things and there’s breathing room. If you pack it too tightly you may not get a full pyrolysis.

Place the lid on your retort, pack the sides with wood vertically, and on top of the lid.

Light the fire. Once the fire is burning nicely place the lid with the chimney atop your barrel and let it burn.

It usually takes a couple of hours for the burn to complete.

Optionally when the fire is done burning and using good quality welding gloves, remove the lids to the barrel and retort then douse the biochar.

I don’t do this because I don’t like getting burned so I wait until the next day to see the results.

My next task is to figure out how to grind it up.

I have also used the biochar for grilling food. It works great! I’m never buying charcoal again.

Please if you have any questions or comments you can find me on nostr.

If you found value in this then please send some back value in the form of sats on the lightning network via nostr or my Alby address
My nostr public key is npub15z2javq62eh2xpms7yew0uzqsk4dr7t3q3dq4903uuxdyw2ca3kstx6q95

Notes an Other Stuff Transmitted by Relays (nostr)

If you’re not on nostr yet then get with the program. It’s way better than twitter, facebook, or any other social media platform you’ve ever used. It’s better because it’s not a platform but a protocol that is very censorship resistant. learn more at

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