Shots Pour Too Quickly - Losing it!

[mdreuben]

La Spaz V2....Programmable Pre-Infusion...both Mini-E and and Mahlkoenig K30 ES Espresso Grinders Double Naked PF...Espro and Bumper Tampers...Various Espressos, including home roasted Dolce....

Starting about 3 months ago, most all of my shots are much too fast, usually in the :15 time period - much too quick.

Both grinders are as fine as possible, practically to the point of touching burrs. I've tried WDT, and other techniques to make sure there is no channeling. The pressure is right in the green on the gauges. I've tried 3 and 6 second PI. The machine has been cleaned using URNEX. Swapped the position of the diffusion screens.

It didn't use to be this way. The shots were totally controllable, nice, even, beautiful extractions viewable with the naked PF.

If I was going to take any kind of educated guess, it would appear that there is channeling going on, but I just can't figure out how. This espresso is fine - very fine. Pressing on it leaves a nice finger print.

Almost too much to bear. Can anyone help?

[JohnB]

The green zone of the gauge shows from 7.5-10 bar. What pressure are you seeing when you pull a shot? I'm really surprised you can grind as fine as your grinder goes & not choke the machine as I can't get within 1 full setting of my zero point without setting off the flow meter alarm. Same issue with 2 different grinders?

[mdreuben]

Followed the advice that ended up being in this forum of changing the screen arrangement. It's now in the alternative position described in the PDF from the forum: s1v1/S1Pix/s1screens.pdf

Getting dialed back in...will let you know how it goes.

Vivaldi Screens.gif (25.11 KiB) Viewed 7955 times

[JohnB]

If your machine worked fine with the standard set up up to 3 months ago why would you think this is the issue?

[mdreuben]

Can't figure out why it started doing this a while back. This was the first time I've tried the diffusers in this position, so we'll see...

[chas]

I will be amazed if the screen trick does anything for your problem. This was mostly a way to get more coffee in the PF in the original S1 when it used a thicker diffuser disk.

If you are grinding finer and finer, you are not choking the machine, and you don't see any obvious fissures it sounds like you are getting side channeling. The solution is probably a combination of grinding coarser and nutating the tamper a couple of times before giving it the full vertical tamp pressure.

[mdreuben]

Got it back under control with the reversed screen. That's all I did differently!

At the very fine grind, the machine choked. I've loosened up the grind and now I'm nailing it at 26 - 30 seconds with :03 PI.

I fully understand that the screen position should have made that much difference. (And would hope that it didn't). But I've been watching all my variables and that's the only one that changed.

[nicfortin]

IMO that "double screen" design is definitely a place for improvement in a future update.
My vivaldi doesn't have the pre infusion and I do get channeling TOO often.

Just receive my second RegBarber, 53.2mm this time instead of 53, hope it's gonna help but I doubt it will be a lot.

my 0.02

cheers
nic