Unfortunately I don't have a bottomless PF or a digital camera to post a video here, but I think my shots have been channeling lately and wanted to ask if the machine could be a reason for channeling?

First some details

- I dose/distribute/tamp into the basket and use the WDT; the basket is not in the PF
- each time I tamp and put the basket in the PF, I'm sure it goes in differently (by that I mean if the basket had markings like a clock, the 6 would not always be pointed to the PF handle
- when I remove the PF after a shot, a 'dent' always appears in the same area (about 2 or 3 o'clock), the dent starts at the edge and moves inward for maybe 10mm, and is only a few mm deep, otherwise the puck is nice and solid
- the resulting shot tastes fine to me, but I've yet to experience a puck without this dent

So, can it have something to do with the machine (showerscreen, position of the machine, etc.)?

Anything I can diagnose and maybe correct?

I have a Brasilia club and Rocky DL.

Thanks.

Hmm, I would suspect the shower screen or water jet breaker if it has one.... have you had the shower screen out to have a look?

EDIT: How does the water stream look with the PF removed? Are you backflushing (water only and/or cleaner and water)?

jesawdy wrote:Hmm, I would suspect the shower screen or water jet breaker if it has one.... have you had the shower screen out to have a look?

EDIT: How does the water stream look with the PF removed? Are you backflushing (water only and/or cleaner and water)?

The part of the group that I can't remove has 5 or 6 holes, then there is a heavy brass screen with 5 holes and a regular shower screen with many tine holes. I'm not sure what a water jet breaker is.

From day one I had them out and soaked them in Cafiza. I've done water only and with cleaner flushes.

I find the water comes out a little stronger on the right (3 o'clock) side, even after a thorough cleaning.

Today I ran a 2 second flush right before locking in the PF and when I removed it later it was an almost perfect puck...just a little dip in that side of the puck...but not as deep as usual. Shot poured nice and tasted great.

Canuck wrote:...I think my shots have been channeling lately and wanted to ask if the machine could be a reason for channeling?

I'm not an advocate of puckology. Apart from the divot, what makes you think there's channeling?

HB wrote:I'm not an advocate of puckology. Apart from the divot, what makes you think there's channeling?

If I never looked at the puck I wouldn't of mentioned it...really no other reason.

Sometimes I think the pour from my double-spout isn't 'perfect', but then I happen to come across videos here or on youtube (I was searching yesterday for videos of extractions from double-spouts), and I came across some from machines like the Brewtus or Livia, and my pours look equal/better, so maybe I'm over analyzing.

Thanks though.

Canuck wrote:...I came across some from machines like the Brewtus or Livia, and my pours look equal/better, so maybe I'm over analyzing.

Perhaps. On the other hand, instead of "eye cupping" the pour, I recommend practicing to discern channeling by taste. Jim's Working the shot maps the taste characteristics and flow time:



An extraction suffering from channeling will be unbalanced towards the latter half: Bland, nondescript, initial sourness with mildly bitter finish. You can intentionally exaggerate this taste difference by dividing the shot into thirds and sampling the last two.