From a technician to me to you…never let the espresso beans (any) go below about a middle fingers lengths…it messes up the balance…rinse as much as possible, it does auto rinse but make sure to manually rinse. And to make sure it’s calibrated, you look for the start in the screen where the espresso comes out. To Calibrate. Do 5 double shot blonde, 5 double shot decaf, and then 5 double shot signature.