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.