Hello, I am using a Brewtus 1 converted to a rotary pump offering manual preinfusion with the middle position of the E-61 lever. Although I really prefer to just start the pump and not use it, I know it can help my shots, but how much preinfusion is needed? Should I preinfuse until some coffee appears at the bottom of the basket? Or, is lesser amount, wetting the surface of the puck acceptable?
Also, when preinfuse starts it would first take some seconds to fill up the chamber of the E-61 head before water hitting the puck - is that correct?
I run about 20 lbs inlet pressure to the pump.
Thanks, Dennis

When I switched over to an external pump & motor and plumbed it in. The factory adjusted brew switch worked that way - allowing mains pressure to flow thru the head w/o the pump on. Actually, it will flow
out the shower screen as soon as I lift the lever to the mid position, so there is no delay to prefill the cylinder first.(simultaneous, as you noted)
I was under the belief that using this feature was better, and didn't realise the stock E-61 chamber did the job so well. I only run the mains input pressure at 20 lbs, because I am afraid of more pressure forcing it's way past my water solenoid and overfilling the steam boiler - then out the vacuum breaker on top to flood the kitchen. I probably should put a solenoid on the pump & motor, but that would eliminate the manual preinfuse feature.Abe Carmeli's machine is set up like that.
It took about 35 seconds to show any drops on the bottom of the basket. Yawn - that is why I never have liked to use this, and then only 10 seconds worth.
The reason I'm considering different techniques is my new versalab M3 grinder has distribution problems.
The coffee comes out the front half of the basket first. Even though I had a level machine, I releveled.
Yesterday, I took the portafilter out and rotated the basket 180 deg before loading it into the group.
That time, the coffee started out the backhalf of the basket. Gotta be the versalab!
I thought if I put more preinfusion into it, that may help, but it did not - I preinfused till drops showed on the basket and the pour still started out the first half of the basket. Thanks- Dennis

denniskeating wrote: The reason I'm considering different techniques is my new versalab M3 grinder has distribution problems. The coffee comes out the front half of the basket first.

It's not your grinder. This is a very common problem with E-61's. Water enters the E-61 brewing chamber from an inlet on its rear side. So, the water jets forward and tends to infuse the front of the puck first. When I had an E-61, I used to front-load the puck a bit to partially overcome this. You can also reduce the effect by installing a smaller gicleur (I did this, too).

I just looked at my baskets thru the ceiling light, and saw two plugged holes, but that was all. I rinse and dry them right away after brewing a shot and have gotten out of the need to soak them like I used to. They looked pretty clear though.
Eric, thanks for your detail on the water distribution.
I enjoy the fast flow of my pump = 130 ml in 10 secs. I have a needle valve on the pumps output side, but usually leave it open. I can adjust the flow down to around 100 ml in 10 secs, then the valve is pretty limited. At either flow rate my brew pressure stays the same at 8.5 bars.
Can adjusting the needle valve accomplish the same results as installing a smaller gicleur?
Perhaps my pump is too frisky, and my extractions would benefit from less water debit.
I screed the coffee in four directions to fill up the center hole the m3 leaves, for uniformity, and tried overfilling the center and front area. Thanks, Dennis

Hello, Today I played with the pump needle valve adjustment and attached a p/f pressure gauge (flow controlled). Full flow 125 ml/10sec = 4 sec pump up to 8.5 brew pressure
Reduced 85 ml/10sec = 10 sec " " " " " "
Does this directly affect the length of time for preinfusion?
If so, I could benefit from a slower flow rate. I can still regulate it down to about 40 ml/10sec - that takes over 20 sec for the pump to pressure up.
Is my needle valve an adjustable gicluer? Thanks, Dennis