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Hardwood Pyrolysis — Soil Amendment, Not Activated CharcoalHomesteader · A few hours · Free from scrap hardwood

DIY Biochar

Burning hardwood with limited oxygen produces biochar — a genuinely useful soil amendment, but not the medical-grade activated charcoal some source pins wrongly call it.

This card covers biochar only — a soil amendment. It is not a substitute for medical activated charcoal, and shouldn't be treated as one in a poisoning emergency; that product requires real industrial activation this process doesn't provide.

Materials

Hardwood only — oak, maple, walnut. Never treated or painted wood.

The Process

  1. Select hardwood, avoiding any treated wood.
  2. Burn it in a closed container with limited oxygen — this is pyrolysis, not open burning, and is what produces biochar instead of plain ash.
  3. Let it cool completely, then crush it into a fine powder.

Correct Use

Soil amendment — biochar improves water retention and provides microbial habitat, but only once it's "charged" with compost or nutrients before use. Raw, uncharged biochar can actually pull nutrients out of soil rather than add them.