The color of high-quality machine-made charcoal should be black and shiny. The charcoal looks pure black from the outside. If the color is black and the percussion sound is not clear enough, it means there is a watering problem, and the amount of water is too high. The whole charcoal is broken to observe the color of the section should be more clear and mellow. If you find yellowing, it means that the charcoal contains more impurities, and the used ash content and volatilization will naturally exceed the standard.
The smell of charcoal does not necessarily have smoke, but if there is smoke, there must be a smell. The smelly charcoal will also have a certain impact on food processing and the mosquito coil industry, and this is also a phenomenon of incomplete carbonization. During the carbonization process, when the kiln temperature reaches a certain level, a hard carbon film will be formed on the surface of the charcoal. This black and bright hard film will thicken with the increase of the kiln temperature. Observe this coating, naturally It can be seen that the charcoal is carbonized. High temperature charcoal and low temperature charcoal can also be easily judged from this.