Charcoal Hub Data

Specification methodology

Moisture Content in Charcoal

What moisture content means in charcoal, how oven-dry testing works, and why moisture affects ignition, burn performance and shipped weight.

Metric Moisture content — the water removable from the sample under specified drying conditions, reported as a percentage of mass.
Last updated 2026-10-07
Data source Public standard methodology (general); not supplier-specific test data
Methodology only — no supplier test data.

This page describes a public standard measurement in general terms. It contains no Charcoal Hub test result and no supplier-specific value. Figures for a real batch come from a laboratory report on that batch.

What It Measures

Moisture content is the proportion of a charcoal sample that is water rather than fuel — the part that disappears when the material is dried. In routine proximate analysis it is the first figure measured, because the later volatile- matter and ash results are corrected for it.

Why It Matters

Water is dead weight in a fuel. It does not burn, and it consumes heat when it evaporates, so higher moisture makes charcoal harder to light, slows the early stage of the burn and reduces the usable energy delivered per kilogram shipped. It also matters commercially: a wet shipment means paying freight and duty for water, and losing usable heat per tonne landed.

Typical Measurement Method

The oven-dry (weight-loss) method: a weighed test portion is dried at a specified temperature — commonly around 105 degrees Celsius for wood-charcoal proximate analysis, with ISO 18134 specifying the general oven-dry procedure for solid biofuels — until it reaches constant mass, then cooled in a desiccator and reweighed. Moisture content is calculated as (mass loss / original mass) x 100. The reporting basis (as-received versus dry basis) must be stated, because the same sample gives different numbers on different bases.

Buyer Relevance

Moisture is a specification buyers should fix in the purchase order, together with the sampling and measurement conditions, because it is the component most affected by shipping and storage rather than by production. A low moisture figure measured at the factory can rise by the time the goods arrive if the packaging is not moisture-resistant, which is why moisture is usually checked both at origin and on arrival.

Limitations

Moisture is not a fixed property; it changes with ambient humidity and storage, so any value is tied to the moment and the conditions of sampling. Sealed-sample handling before testing matters — an unsealed sample left in a humid room will read high. Different drying temperatures and hold times also give different results, so figures from different laboratories are comparable only when the method is the same.

Data Source

Public standard methodology (general); not supplier-specific test data

  • Method family cited in general terms only; no laboratory result is published here.
  • Last updated 2026-10-07.
  • Measurement uncertainty applies to any real figure derived by these methods and should be reported with it.

Relationship to the other proximate figures

Moisture is measured first and is then subtracted from the other results, so an error here propagates into volatile matter and, through it, into fixed carbon. Ash content is reported on a dry basis precisely to avoid this dependence.

What a buyer should ask for

  • The moisture figure and the basis (as-received or dry).
  • The drying temperature and hold time used.
  • Whether the sample was sealed and how it was transported before testing.
  • An arrival check on the landed batch where packaging is not moisture-barrier.

For batch-specific moisture data, request a quote; for the laboratory view, see the testing sub-site.

Where to go next