I wanted to improve the taste of my shots, so I began looking at brew pressure.

I have typically used 18 grams of espresso to yield 30 grams output in 25 seconds. I adjusted the pressure with a blind portafilter up to 10 bars, but when I am brewing the shot, it rarely exceeds 6 bars of pressure. I've noticed after the shot, it creeps up much higher, but not during the shot.

I was also told a rule of thumb is 2 ounces in 25 seconds. With my current grind and tamp, I am close to that, also.

I'm not sure I can adjust the pressure upwards much more. Should I attempt to increase it so that the pressure during the pull is closer to 8 or 9 bars?

Thanks!
David

I like 8-9 bars during the initial part of brewing.

It seems very odd to me that you're getting 10 bars with a blind pf in place, but not even approaching 8 when pulling a shot. I think you're going to need someone more knowledgeable than me to help you fix that. I mean, even if you had the water gushing through the puck, you should still be getting at least 8 bars during the shot. Question though...when you've got the blind pf on and activate the pump, does it shoot up to 10 bars rapidly, or is there a delay?

Thanks. There is a delay. I watched the WLL video on changing my own pump and was discouraged....don't really want to spend a day doing that. Then I watched their pump pressure diagnosis video and mine failed miserably, so I'm going to ship it in for a pump replacement, tune-up and whatever else it needs after 4 years of service or so.

David B.

The pressure and flow are connected. If you reach 10 bar with blind portafilter = no flow, you cannot reach 10 bar, when there is water pouring out of puck. It must be (physics is physics) lower.
I think you will have to adjust it little bit tighter (11 bar) and also adjust little fine grind to get the results you want.
Or adjust the overpressure valve on the coffee directly, not with the blind filter. But you should do it at one time, because the grind can change over time.