The present invention is an improved method to grind coffee where grinding speed can be adjusted either on demand or according to a programmed profile. By lowering the rotational speed of the grinding burrs, the user can insure more consistent particle size for types of coffee or methods of brewing where it is desirable, or dramatically increase speed for greater productivity. By incorporating a load cell, the grinder is able to identify coffee brewing device and deliver portioned ground coffee according to program settings or user input. The device also features an improved hopper design to reduce waste and ease whole bean removal. More importantly is a new method to calibrate the distance between the grinder mills and to automatically adjust grinder particle size so that a given numerical value is consistent for each grinder and every user.
