Thermal pretreatment serves for reducing the adhesion forces between the shell and kernel. The shell of the cocoa bean is naturally completely smooth. Its surface shrinks initially through fermentation and drying. This process gives rise to strong adhesion between the shell and cocoa kernel.
The ShellCon unit returns the bean to its original shape. The bean is expanded, so that the kernel again clearly loosens from the shell.
The beans are fed into a continuously rotating drum. A continuous guidance system inside the drum ensures uniform movement with good intermixture and a defined residence time. With a small addition of water, the moisture in the shell is first increased. The heat produced by the system then causes the bean to expand – the so-called balloon effect. In this way, separation of the shell from the kernel is ideally achieved, creating the basis for high product yield in the subsequent dehulling plant.