RNAV wrote:When I initially received my Niche, I calibrated per DaveC's video and haven't touched the calibration ring since. Recently I've been brewing a lightly roasted Ethiopian and have been taking the calibration mark past 0 into what would be negative numbers.

I really liked LObin's suggestion of calibrating to true zero as that would give me usable reference marks with this Ethiopian, and I only ever brew espresso. So, I completely cleaned my grinder.



Like you, I didn't feel comfortable touching the burrs while running the grinder . . . I know you can do that with flat burrs, but didn't know if you could do it with conicals. So, with the machine off, I firmly hand-tightened the burrs until they touched, then moved the calibration ring's indicator to the 0 mark.

For me, the difference was 27 clicks on the calibration ring. On my grinder, 1 click on the calibration ring equals 1.5 indicator marks. So, 27 clicks x 1.5 marks = 40.5 change in grind indication. I was at -2, so I set the grind setting to 38.5 and pulled a shot -- spot on, yielding the exact same preinfusion time, shot time, and yield (note: I ground 2 doses worth and tossed prior to pulling a shot to account for any retention post-cleaning).

I've been keeping records of grind settings for previously brewed espressos, so now all I need to do is add 40.5 to whatever those setting were in order to achieve the same grind. I think I'll keep it like this for a while and see how it goes.