How it works
Traditional shelling machines press the nuts through slots to release the kernels from the shell. This works well with nuts roasted in the shell, but poorly if they are sun-dried. The machines are generally made of wood, to close tolerances, by skilled craftsmen. They are expensive, generally require several people to operate and have limited capacity and lifespan. The Malian Sheller, however, rolls the nuts in an ever narrowing space, between two concrete surfaces, at ever increasing speed. The machine is loaded with about a litre of nuts. The handle is then turned quickly for about 20 seconds. The kernels and shell fragments fall into a shallow basket and are winnowed.