Bargain Braai Supplies sells the following quality brands:
- Surebraai Charcoal
Wood is broken into pieces of the proper dimension in a hammer mill. A particle size of about 6cm is common, although the exact size depends on the type of wood being used. The wood then passes through a large drum dryer that reduces its moisture content by about half (to approximately 25%). Next, it is fed into the top of a multiple-hearth furnace (retort).
Externally, the retort looks like a steel silo. Inside, it contains a stack of hearths. The top chamber is the lowest-temperature hearth, on the order of 275°C, while the bottom chamber burns at about 650°C.
Within each chamber, the wood is stirred by rabble arms extending out from a center shaft that runs vertically through the entire retort. This slow stirring process ensures uniform combustion and moves the material through the retort. On alternate levels, the rabble arms push the burning wood either toward a hole around the central shaft or toward openings around the outer edge of the floor so the material can fall to the next lower level. As the smoldering char exits the final chamber, it is quenched with a cold-water spray. It may then be used immediately, or it may be stored in a silo until it is needed.