Commercial charcoal is found in either lump, briquette, or extruded forms:
Lump charcoal is made directly from hardwood material and usually produces far less ash than briquettes. Pillow Shaped Briquettes are made by compressing charcoal, typically made from sawdust and other wood by-products, with a binder and other additives. The binder is usually starch. Some briquettes may also include brown coal (heat source), mineral carbon (heat source), borax, sodium nitrate (ignition aid), limestone (ash-whitening agent), raw sawdust (ignition aid), and other additives.
Hexagonal Sawdust Briquette Charcoal
Hexagonal Sawdust Briquette Charcoal are made by compressing sawdust without binders or additives, making it completely natural. Hexagonal Sawdust Briquette Charcoal is the preferred charcoal in countries like Taiwan, Korea, Middle East, Greece. It has a round hole through the center, with a hexagonal intersection. Mainly for BBQ uses as it does not emit odor, no smoke, little ash, high heat, and long burning hours (exceeding 4 hours). Just pure wood aroma for the BBQ meat.
Extruded charcoal is made by extruding either raw ground wood or carbonized wood into logs without the use of a binder. The heat and pressure of the extruding process hold the charcoal together. If the extrusion is made from raw wood material, the extruded logs are then subsequently carbonized.
Japanese charcoal removes pyroligneous acid during the charcoal making. Therefore when burning, there are almost no stimulating smells or smoke. The charcoal of Japan is classified into three kinds.
White charcoal (Binchōtan)
White charcoal (Binchōtan) is very hard and has a metallic sound
Ogatan is made from hardened sawdust. It is most often used in Izakaya or Yakiniku restaurants.
The characteristics of charcoal products (lump, briquette, or extruded forms) vary widely from product to product. Thus it is a common misconception to stereotype any kind of charcoal, saying which burns hotter or longer etc.