Hello I have a Gaggia Classic (not pro) from 2014 and I'd like to adjust the OPV down to about 9 bars. Without investing in a pressure gauge, is there a standard amount of turning the hex screw to achieve 9 bars or is every unit a little different? I've heard anywhere from a quarter turn to a turn and a half is necessary to achieve 9 bars. Thanks in advance for any advice.

Jason

Usually around 270° anticlockwise gets me to around 8.5-9 bars on the gaggia classics I have worked on. You can also do a test without a pressure gauge where you measure the outflow from the OPV with a blind basket inserted. I think the magic number is around 130ml or 130g. Just remember when you reduce the pressure you'll have to grind finer as you'll see your shots running FASTER since there is less compression on the puck.

Thanks so much for your help Beerwiffle. My Baratza Virtuoso is already at second lowest grind setting with lighter roasted Ethiopian beans so maybe I should skip this adjustment.