The micro void disperses widely within bamboo charcoal, the diameter of which is up to 10-7m from 10-3m.

The bamboo charcoal is made of 4-year old bamboos, which are more stable than 3-year old ones that contains more moisture and has higher perentage of shrinkage and changability, which are not suitable for bamboo charcoal burning. After cut, washed, and chopped, bamboos are smoked and dried naturally in order to control its moisture with 15%. With these complex steps, bamboo charcoal with high quality is produced.

To make bamboo charcoal, put bamboos into the kiln and keep burning them until the temperature inside kiln reaches to 250°C. Bamboos now are coal charring(the first coal charring). In the beginning of coal charring, the temperature within the kiln reaches rapidly to 350-400°C. When the first coal charring finishes, workers release large air into the kiln in order to heighten temperature to 750°C, called the second coal charring. The purpose is to decrease impurities and volatility within bamboo charcoal, whose hardness and content of carbon are higher. In the end, the kiln is sealed up carefully for a week. Later open up the kiln and select useful bamboo charcoal out.