The production process, stage by stage

By Mohamad Sinno, Charcoal Expert · published 7 September 2026. Not reviewed by the Head of QC — the reviewer byline on our older production pages carries the date those pages were read, and this one has not been read yet.

Every page about this recites the same stage list, because the stage list is not in dispute. What differs between factories is where they sample, what they record, and which figures they are willing to attach a source to. Those are the three columns below.

The stage map, and what each stage decides

Six of these eight are formal sampling stages for us — pieces pulled at random, at least five pieces per 50 kg, with weight, ash content, moisture, ash colour recorded each time. The "sampled" column is the one worth comparing against any other factory's account of itself.

One naming point, because the market uses both words: our forming line is extrusion, not hydraulic pressing. Different machines, different densities, different failure modes — and it is the word our own checkpoint list uses.

From order to loaded container the calendar is 15 working days (20 ft) · 20 working days (40 ft). The quality system that runs across these stages is the nine checkpoints.

Where the sources disagree, and by how much

Two parameters on this SERP have no agreed value at all, and the spread is large enough that a buyer should know it rather than be handed a midpoint.

Binder share: three ranges, no overlap

The outer two do not overlap, so there is no market consensus to average toward. Ours sits below both, and the reason is worth stating as a trade-off rather than a boast: less binder means less of the finished piece is starch, and more of what a laboratory measures as volatile matter comes from the charcoal. It also means the mix has less margin for error. What the binder does to the finished briquette is on the binder page.

Carbonization temperature: a number that circulates

A single carbonization figure — 590 °C — appears on multiple machinery-vendor pages, and that is the most accurate thing anyone can say about it. The page we tried to read it from answered with its own blog index rather than the article, so we cannot cite it to a source; it is a number that travels, which is a different status from a number that was measured. Broader bands are published too, in the 400–600 °C region.

Our own kiln temperature and kiln type are not published here, and the reason is on the carbonization page, which is also where the yield-versus-fixed-carbon trade-off is set out from a source that could actually be read.

The batch journey we cannot publish

The section that belongs here is one batch followed from shell to container — dates, stage records, the lot anonymised. We do not have it to publish. The drying log and the container loading log are not published, and no sample page of either has been supplied.

A journey assembled from plausible dates and plausible readings would read as exactly the proof this page wants, and would be a story. What does exist, and is checkable, is the record per batch — ash content, moisture, burning time, drop test, cracks, temperature — reachable from the code on your carton, since The batch code identifies the production batch whose QC file holds the laboratory COA and the factory’s own results.

What the stages produce, measured

The output of the whole chain is on 3 certificates from one laboratory: ash 1.20–1.58%, fixed carbon 77.03–80.84%, volatile matter 16.61–18.33%, moisture 1.35–3.06%. Three batches across six weeks, published as the spread they are rather than as a promise about the next container — which is itself a fact about the process, and is traced in why batches vary.

After packing, the goods sit through a weathering hold; packing-day temperature is recorded; cartons travel enclosed in a thermal blanket inside a vacuum-sealed load with headspace to the ceiling and a gap at the door. That is where the drying stage's work is either kept or lost, and it is set out on the drying page.

Deep dives

• Carbonization — the yield-versus-fixed-carbon trade-off, the phases a producer publishes, and why our own kiln figures are stated as absent rather than inferred.
• Drying and moisture control — our oven figures beside a competitor's window that does not reconcile with them, and the micro-crack physics that explains why the difference matters.
• The tapioca binder — what it does, at what share, and what it contributes to a volatile-matter reading.