Charcoal problems, diagnosed

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

Every supplier page about charcoal defects ends the same way: the cause is somebody else's charcoal, and the remedy is theirs. This one ends where a complaint actually has to end — at the code printed on your carton and the window you have to raise it in.

Symptom index

Find the symptom, run the check, and keep the result beside the batch code. The last column is where the procedure is written out.

Note how often "Both" appears in the third column. That is the honest answer and it is the one most of this category will not give you.

Production side, buyer side

A defect argument is usually a disagreement about where the fault arose, so it is worth being clear about which of these a factory can control and which a warehouse can undo.

Ours is sampled at random, at least five pieces per 50 kg at 6 stages — carbonization, screening, grinding, mixing, extrusion, drying — recording weight, ash content, moisture, ash colour. Per batch the file holds the laboratory COA and the factory’s own results for the batch: ash content, moisture, burning time, drop test, cracks, temperature. That is the evidence a claim is argued against, and it exists whether or not anyone asks for it.

The measured baseline behind the commonest complaint

Moisture is named as the cause of more symptoms than anything else in this category — sparks, cracks, weak ignition — and almost nobody publishes a measured value beside the claim. Ours, from three certificates:

Those are measured samples, not a specification, and they are not a promise about your container — the target at packing is a different figure taken at a different moment, and the moisture page keeps the two apart rather than reconciling them. What they give you is a baseline: a number to compare your own oven check against. Ours is drying oven at 120 °c for 5–10 minutes — a quick check, not the constant-mass method.

One gap, and we are not filling it with someone else's test

The odour row is the weakest one here and it is weak on our side. Several suppliers publish a smell test; we have no first-party odour check on our data sheet at all — not a stage, not a method, not a pass criterion. What we can state is what the factory controls: the binder is tapioca at a typical 1.5–3% of the mix, and sampling happens at mixing, extrusion and drying, which are the stages where an odour cause would act.

Borrowing a competitor's burn test and presenting it as our procedure would close the gap in a sentence and would be false. It stays named until a real check is recorded, and the odour page says the same thing at more length.

The triaged complaint we do not have

A worked example belongs here — a real distributor's multi-symptom complaint, anonymised and triaged in public, showing which symptoms traced to production and which to a warehouse. We do not have one to publish. No such correspondence exists in anything this site holds, and The drying log and the container loading log are not published, and no sample page of either has been supplied.

An invented case study would be easy, unfalsifiable and exactly the sort of evidence this page teaches you to refuse. So the gap is named instead. What the section would have shown is already in the two tables above; what it would have added is a story, and a story is the part you should not have believed anyway.

Turning a defect into a claim

1. Photograph the carton code first. Ours is a four-digit batch production code, two letters identifying the packing team, and one check digit. Without it you have a complaint about charcoal in general.
2. Run the check for that symptom from the table above, and write down the conditions before the result.
3. Ask for the batch file, not "the COA". The batch code identifies the production batch whose QC file holds the laboratory COA and the factory’s own results.
4. Raise it inside the window. Ours is seven days from receipt for quality and quantity claims, after which the goods are deemed accepted; the remedy is replacement or credit on the next order.
5. Know what a failure means on the production side. When an in-process check fails — moisture, drop test, cracks, odour — the batch or the failing part of it is rejected and does not ship. No re-drying-and-retest route is claimed.

Common questions

Is the problem the charcoal or my storage?

Often both, and the way to separate them costs nothing. Open a second carton with a different batch code, and change how you light one of them. If the symptom follows the code, it is a batch question; if it follows the ignition or the room, it is a handling question. Charcoal is hygroscopic and takes up moisture from the air, so a piece that left the factory dry can arrive at a humid warehouse and behave differently.

What is the first thing to do when a batch behaves badly?

Photograph the code printed on the carton, before anything else. Ours is a four-digit batch production code, two letters identifying the packing team, and one check digit. Every question after that one — what the certificate says, what the factory recorded, whether a claim is arguable — depends on being able to name the batch.

What happens at your factory when a check fails?

The batch, or the failing part of it, is rejected and does not ship. We claim no re-drying-and-retest route, because we do not run one. Checks happen at six sampling stages and again per batch, where the file records ash content, moisture, burning time, drop test, cracks and temperature alongside the laboratory certificate.

How long do I have to raise a problem?

Ours is seven days from receipt for quality and quantity claims, after which the goods are deemed accepted; the remedy is replacement or credit on the next order. Whatever your supplier’s window is, find it before the container lands — a finding that arrives after the deadline is a conversation rather than a claim.