i have recently purchased a portafilter gauge and ran some tests on my silvia to measure the actual pressure value setting on the OPV of the unit.

the gauge measured 10bar of pressure, but my question and possible concern is with respect to the time it took to reach maximum pressure - which was 2bar in 5seconds, and climbing to max 10bar by 7seconds. is the long ramp-up time (to even make a difference on the gauge, and then a full 5seconds to reach 2bar) a concern?

does ramp-up pressure speed change with an empty portafilter + portafilter pressure gauge, versus the pressure when pouring a shot through a puck in the portafilter? do i even need to be concerned with the ramp-up time to max pressure?

i guess i could get the remaining components and install the gauge to the unit directly, but was just curious if anyone has ever come across any inconsistencies or inaccurate readings from utilizing the pressure gauge on with an empty portafilter.

on a side note, i adjusted the OPV on the silvia until i measured 9bar max. does anyone have any opinions on whether or not is this optimal for the silvia?

localhost127 wrote:is the long ramp-up time a concern? do i even need to be concerned with the ramp-up time to max pressure?

No and no, that's normal for a vibratory pump.

does anyone have any opinions on whether or not is this optimal for the silvia?

Most agree that around 9 bar is a good starting point. You'll read plenty of threads talking about the difference in pressure measured against a blind filter versus during a pour being somewhere between 0.5 bar and 2.0 bar. I wouldn't obsess over the gauge reading; instead, focus on taste/texture and adjust accordingly.

I recommend starting at 9 bar whatever your gauge reads and adjust up/down 1 bar as desired. If you have trouble with channeling, lower the brew pressure since it decreases the likelihood of channeling. From there, it isn't difficult to judge the brew pressure by taste/texture. If the pressure is too low, crema production falls off and taste will go flat. If the pressure is too high, crema production increases and bitters creep in due to overextraction.

I recently watched a video from Whole Latte Love on how to adjust the OPV on a machine. They stated that 10bar at the group is really 9bar under normal use. However, this may have been specific to the machine they demo'd on.