Method for controlling a coffee machine grinder

A method for controlling a coffee machine grinder comprising measuring an actual value of a physical quantity relating to a percolation process and modifying a ground coffee grain size at least for the subsequent percolation so as to compensate for a possible detected deviation between said actual value and a reference value for said physical quantity,

• wherein as a consequence of user changes for the coffee machine, the control unit commands the execution of a preliminary coarse adjustment of a gap between grinding wheels by actuating an adjustment ring nut, and wherein when a rolling friction moment is created between the grinding wheels to block their reciprocal rotation, an activation signal is automatically generated for activation of an actuator of the adjustment ring nut to widen the gap between the grinding wheels so as to remove the source of the block.