Nunas wrote:If you add the flow kit (with or without the gauge), you'll be able to change the nature of your shot profile. One way to use it is to start the shot with the valve closed, then lift the lever and open the valve a bit. This controls the preinfusion time. For the middle third of the shot, run the valve at about 1.5 turns open, which is about the same jet setting as a stock e61. Then gradually close the valve for the last third, simulating the pressure drop off of a spring-type lever machine. You don't really "need" the gauge to do this, as you can judge by flow of the espresso instead of the pressure..

I don't see that much is to be gained installing this flow control mushroom if your machine is direct plumbed and particularly if it's DB with a rotary pump. The most revealing tool would be a bottomless portafilter to allow monitoring of flow.

What I am now doing (with unmodified mushroom) is line preinfusion of about 5-Bar for about 25-seconds, based on how the shot is developing, then going to pump 'ON' mode for about another 35-40 seconds and then back down to line level 'post infusion' to finish off the shot.

I would be interested to hear from someone who had previously used this method before modifying their group with the flow control mushroom to get their take on what the difference in taste might be.

Perhaps this needs its own thread.