The Grind—Particles and Particularities

Grinding of roast coffee beans is required to make soluble substances available for extraction. The average particle size and a tailored particle size distribution (PSD) are decisive for transport, storage, dosing, and extraction of the roast and ground coffee. They determine how easily the coffee powder flows, how quickly it releases gases, how fast the water can percolate through the coffee during extraction, and finally what in-cup quality one may expect. Therefore, grinders are more and more precise tools that allow for consistent and repeatable production of a narrow PSD with a low amount of fines, which in principle allows for a highly effective extraction. Operators and baristas have to choose the appropriate grinder for the intended brewing method. Eventually they become the skilled craftsmen who guarantee, when in perfect control of the grinder, for the perfect cup of coffee.