A key ingredient of chocolate is cocoa powder which is made from cocoa beans. The process that begins with the raw cocoa bean and ends with cocoa mass includes several stages among which are cracking and stripping them of their shells. What remains is the inner part of the kernel, the so-called 'nib'. The nibs are heat treated to eliminate possible bacteria. Subsequently, they are roasted and ground so that a fluid cocoa mass emerges. The 'nibs' will be alkalized before, during or after the roasting process. It is the latter which determines the color and taste of the cocoa mass.
This mass is an intermediate finished product supplied to the chocolate industry and constitutes the basis to produce cocoa powder and cocoa butter. By means of presses, the cocoa butter is extracted from the mass leaving the so-called cocoa press cakes remaining.These cocoa press cakes are disks with a thickness of approximately 50 millimeters. These cakes are first broken up into smaller pieces, and then ground into cocoa powder, whose grain size can be specified.
Cocoa powder is the final product emerging from the grinding and stabilizing process of cocoa press cake, and the powder comes in numerous varieties determined by color, fat content and taste. These in turn depend on both the origin of the beans and the manufacturing processes.
NEUMAN & ESSER and Duyvis have been partners in the processing of cocoa press cake since 1996. In this cooperation, we take over the grinding of the cocoa powder. Our Dutch partner Duyvis is the world's leading supplier of cocoa processing machines. As part of this partnership, a classifier mill has been specially developed for grinding cocoa press cake.
The pre-ground cocoa cake kibbles are stored in a silo then passed through a metal detector, which detects the possible appearance of unwanted metal particles in the product and separates them off where necessary. The feed airlock feeds the kibbles via the pneumatic conveying system into a NEUMAN & ESSER impact classifier mill ICM. In the mill the kibbles are pulverized to a very fine powder and classified. After pulverization and classification, the product enters the product filter, the cocoa collector. In the cocoa collector the product is separated from the air and discharged. The process air is than led to the air conditioning unit. The air conditioner successively filters, cools down and dehumidifies the process air.
After grinding the product is forwarded to the next process step: crystal growth. The cocoa powder is led through into the pneumatic conveying system of the stabilizing process. Here too the air is specially conditioned. The heat exchange during transport ensures that the powder is cooled down and further stabilized under specific/specified conditions. After that stabilization the powder is separated again from the process air in another cocoa collector. The cocoa powder will be discharged, and is then ready to become a very tasty chocolate – after further processing of course.