Beverage processing: grinding coffee

Almost all coffees sold are ground industrially by metallic micrometric grinding cylinders assembled in pairs.

Beans must be hard brittle and cold. Grinding is easier when the roasting process was intense. Light roasting yields beans that are soft and tend to be flattened during grinding rather than being reduced to powder.

During grinding, carbon dioxide contained in the coffee bean escapes – this is the degassing of the bean.

The extent of grinding determines in part organoleptic qualities in the coffee.

When the grind is too fine, the procedure for preparing the beverage is long; the water has time to cool so that it draws down particles that sink to the bottom of the cup. The coffee is then muddy and acrid.

When the grind is too coarse, the water filters through too quickly and the coffee’s savor is bland.

During filtration, the optimal rate of extraction is 18 to 22% of the weight of the ground. Ground coffee must be wrapped quickly n order to avoid oxidation and loss of aroma. It is vacuum packed less than eight hours after grinding.
Beverage processing: grinding coffee