timo888 mentioned
Preinfusion: I do a partial pull with my hand restraining the lever so the spring is not decompressing under its own (full) force.

Yes, I also restrain the force of the spring during preinfusion, thinking, "Slow, smooth."

grong wrote:Yes, I also restrain the force of the spring during preinfusion, thinking, "Slow, smooth."

Really, it seems as though this would be more of an "enhanced" preinfusion. My understanding is that holding the lever down for a short few seconds really would be the preinfusion. What I do after that hold-down time is to release the lever in as smooth a motion as I can... I guess I do effectively resist the spring, and lower the brew-pressure, a bit in doing so.

RAS:
Really, it seems as though this would be more of an "enhanced" preinfusion.

Slow, smooth. Yes, enhanced, dynamic, and a good distinction. It does take a number of seconds to accomplish, so it is soaking the puck under some pressure, but not in the tradition of holding the lever still during the process, i.e. preinfusion. Again, the reason I do this is that I run my pressure so low, topping out at .8. And a big reason I do this at all is to add volume, but I do not taste a downside.

A plumbed in machine or a machine running at higher pressure would provide a good bit of water under pressure to the puck, preinfusing with the lever held still.