A five-minute espresso dial-in routine
New bag, same routine. Start at 18 g in, aim for 36 g out in about 28 seconds. Change one thing at a time.
Too fast and sour: grind finer. Too slow and bitter: grind coarser. If it's fast and bitter, the puck is channeling; check distribution before touching the grinder again.
Two shots is usually enough to land within a few seconds of target. A third confirms it. After that, stop fiddling; most of the remaining variation is the beans aging, not you.
Write the setting on the bag. Future you will not remember.