After a lot of coffee beans, I have noticed that the best results are often with the pressure outside the espresso area. Like TomHughes recommendations I decided to ignore this gauge.
At the same times I made some internet search, and found 2 workarounds to limit the brew pressure. One with an electronic pump speed control from @joey24dirt (on this forum). And the second by using the safety valve. I decided to try this mod.
I was surprised how that was easy, at first I was a bit afraid to broke the opv, but it doesn’t seem to be so weak, just need to be careful to get out the lock clip.
There is a factory mark on the opv.
I began with 1 counterclockwise turn, then 2 and got this pressure limitation.
At 3 counterclockwise turns,
I noticed here the pressure was a bit shaky,
but I stay here, because that should be 9 bar, by referring to this table.
So, what are issues to brew with a to high pressure, outside espresso recommendations, I don’t know what exactly but probably not so good to avoid channeling, ... if you have more information about this, please share.
First shots, without changing the grind size, do not seem to significantly change the ratio, but all seems softer, less shaky especially at the end of extraction. Pucks was very flat and dry. Tastes was really interesting, less bitter with this blend arabica/robusta, is that subjective, yes ; is that scientific, no; it was a blind test, no and unfortunately I have just finished my batch of beans, need to get out the next one from the freezer. And now need time to drink coffee ( at lot of coffee ) to form an real opinion.
Ah, one thing more, yes you get more water in the drip tray
inside the opv