Prior to the extraction process, roasted coffee must be ground and pre-wetted in order to facilitate the subsequent extraction process. Grinding takes place in a specially designed mill. The purpose of the grinding is to reduce the coffee beans to a particle size more suitable for the extraction. Further, water is added to the granulated coffee in order to improve the extraction process.
Granulation of the roasted coffee beans prior to the extraction is an important process step. The objective of the granulation step is to achieve a narrow particle size distribution with a minimum of fines created.
In order to obtain this, GEA Niro has developed a setup with two roller mills and a screen. With this equipment, a desired particle size distribution of approx. 3 mm as mean particle size and a fraction below 1 mm of max. 5 % can be achieved.