Without a known zero reference, grinder numbers are hard to reuse. Use one consistent method for your setup: burr touch (if supported), chirp/sound point, or factory index mark.
Find zero safely and document method
Use manufacturer instructions first. Zero definitions differ by grinder, and manufacturer guidance overrides generic internet advice.
If your model supports burr-touch zeroing, do it with an empty grinder and running burrs, then back off immediately at first contact cue.
If burr-touch is not supported, use chirp or factory index
For grinders without safe burr-touch access, use the first consistent chirp/sound cue or the manufacturer's factory index mark as your reference.
Do not force burr contact on grinders that are not designed for touch-point calibration. Consistent reference beats risky mechanical contact.
Recalibrate after real mechanical changes
Recalibrate after burr swaps, carrier alignment work, or major cleaning where burr position may shift. Do not assume old zero survives hardware changes.
If expected settings drift by more than your normal range for multiple bags, confirm calibration before blaming beans or water.