We all know that machines equipped with 3 positions brew switch that open the solenoid valve for line pressure to wet the coffee puck before switch on the pump have great benefit.

What if we turn the switch to this position for a little while at the end of brewing process before turn it to OFF position? I guess it might do more good than harm because the solenoid still remains open and pressure slowly reduce. Just like mimicking the spring loaded lever machine.

Have anyone with 1 group Synesso or Speedster tried this? Is this speculation viable? Will it alter the taste of the shot?

Its on my list of things to do as soon as I can get access to my pressure regulator to increase the line pressure to around 5 bar, its currently set at around 2.5 bar and I think it needs more oomph. I've also just made a pressure gauge with a variable bleed adjustment so that I can see the effect of the change from Line - Pump - Line at the puck, as these changes are all downstream of a .6mm restrictor. Anyone who is interested, also just had a Speedster group cap spun out of 1.6mm Stainless Steel and polished to a mirror finish... I just hope the M8 nut I had them weld on the inside is dead centre. I will know when I get home in a couple of weeks, got two done, so I may have one spare... never did like the black group cap on the Speedster or the GS3 for that matter.

I did mod my machine to control the solenoid manually (see here). Once the pump is off (but valve is still open), it takes ~3secs for the pressure to drop from brew pressure to line pressure. IMHO, that's way too short for anything meaningful to happen.


EDIT: IIRC, a spring lever takes something like 20sec to get from highest to lowest pressure. So now you have meaningful numbers 3 VS 20 .

Thanks coffee.me for confirmed that this is doable.

I think 3 sec might be meaningful because the purpose of reducing brew pressure at the end of the extraction is to reduce overextract solid? Can you taste the difference? Please also try pulling off the cup before kicking the solenoid open to release pressure too.

Not really, Suksit. Do a search here on "lever pressure profile" and read the wealth of info on the topic, very interesting stuff that isn't going to be replicated by keeping the solenoid open after the pump is off.