What is on a specification sheet?
A specification sheet is written by the supplier to describe what it promises. A certificate of analysis (COA or ROA) is issued by a lab after testing a sample from a specific batch. The first is a promise, the second a measurement. When you order, have the key specifications written on the proforma invoice, and if you need a certificate of analysis for your batch, agree on it before production.
Our specifications by quality grade:
- Ash1.6 – 3%
- Fixed carbon75 – 80%+
- Moisture5 – 8%
- Burn time60 min – 2.5 h
Details for each grade are in coconut charcoal grades compared and on our quality page.
Fixed carbon
The solid part of the charcoal that burns slowly and gives long, steady heat. The higher it is, the more energy each piece stores and usually the longer it burns. Good coconut hookah charcoal is typically 75% or more.
Most labs do not measure fixed carbon directly; they calculate it by subtracting moisture, ash and volatile matter from 100. So an error in any of those also changes the fixed carbon figure.
Moisture
The water content of the charcoal. High moisture slows lighting, can cause crackling and sparks, reduces useful heat, and means you pay for water in every ton. Our maximum is 5% for Platinum, 6% for Super Premium and 8% for Premium.
Charcoal absorbs moisture from the air after production, so moisture on arrival can differ from the factory figure if packing or storage is poor. Read how to store hookah charcoal.
Ash
What remains after complete burning. Low ash means less cleaning of the bowl and better heat transfer, and ash color matters commercially too: white is preferred over grey. Covered in detail in hookah charcoal ash content.
Volatile matter
The components that turn into gas when heated, before the carbon burns. A higher figure means easier lighting but can also mean smoke or smell in the first minutes. Well-carbonised hookah charcoal has a low volatile content, which is one reason it gives no noticeable smell once fully lit.
Calorific value
The amount of heat a kilogram of charcoal gives, usually in kcal/kg. It is linked to fixed carbon and moisture: more carbon and less moisture mean a higher calorific value. When comparing suppliers, make sure the values are measured the same way (gross or net, and on the same basis).
Physical tests: drop test and size
- Drop test: 10 pieces are dropped from 1 metre and the intact pieces counted. Our results: Platinum 8–10 out of 10, Super Premium 7 out of 10, Premium 5–6 out of 10. Higher means less breakage in shipping and handling.
- Size and tolerance: the stated size (25, 26 or 27 mm for cubes) determines pieces per box: 72 pieces at 25 mm, 64 at 26 mm and 56 at 27 mm per 1 kg box.
The comparison trap: testing basis
Two suppliers can send numbers that look different but are actually similar, or the opposite, because they were measured on different bases:
- As received (ar): the sample as it is, with its moisture.
- Air dried (adb): after the sample has stabilised with room humidity.
- Dry basis (db): after all moisture is removed. Figures on this basis look higher for fixed carbon and slightly higher for ash.
Always ask which basis the figures are on and which test method was used, and never compare a dry-basis figure with an as-received one. For more questions to ask before signing, see 10 questions for any supplier.
Frequently asked questions
What is a good fixed carbon percentage for hookah charcoal?
For good coconut hookah charcoal it is usually 75% or more. Ours ranges from 75% in Premium to 80% or more in Platinum and Super Premium.
What is the difference between a COA and a spec sheet?
A spec sheet is the supplier's promise of what it will produce; a certificate of analysis is a lab measurement of a sample from a specific batch.
What moisture level is acceptable in coconut charcoal?
Between 5% and 8% depending on grade. Higher moisture slows lighting, reduces heat and can cause crackling.
Why do two suppliers show different numbers for the same quality?
Usually because of a different testing basis (dry vs as received) or test method. Ask for the basis before comparing.
Are written specifications enough to judge quality?
Not on their own. Test a sample yourself, visit the factory if possible, and have the specifications written on the proforma invoice.
Further reading: