Puck defect? What is happening here?

#1: Post by **Armand** » June 2nd, 2014, 7:42 am

Everytime I make an espresso I see the following defect in the puck, always the same place, though I don't see any grinds sticking to the screen

#2: Post by **Nate42** » June 2nd, 2014, 8:23 am

99% chance it means exactly nothing. But here's a trick that you can do to see if it has anything to do with your distribution and tamp. Prepare you shot as normal, but just before you lock in the portafilter rotate the basket in the portafilter by 90degrees. If your prep had anything to do with it, your defect will have moved by 90 deg. If that's the case work on your distribution. If that's not the case, I wouldn't sweat it.

#3: Post by **TomC** » June 2nd, 2014, 8:33 am

Armand,

How big is your dose?

June 2nd, 2014, 9:01 am

By the look of the puck, I'd say bigger than it should be.

#5: Post by HB » June 2nd, 2014, 9:33 am

I agree with Merle/Tom that the dose looks too high. Try the nickel test, i.e., place a nickel on the dry puck, lock in and then remove. It should leave little or no impression. Based on the photo above, I think the puck is crashing into the dispersion screen and a dose reduction of 2 grams will help consistency.

June 2nd, 2014, 9:39 am

Great advice here by Dan. Also, if this is how you've been dosing, I'd pull off the screen and give it a good soaking/cleaning. You might be surprised to find it in serious need of cleaning.

#7: Post by **TomC** » June 2nd, 2014, 10:00 am

uscfroadie wrote:By the look of the puck, I'd say bigger than it should be.

I was going for the subtle route

June 2nd, 2014, 12:04 pm

TomC wrote:Armand,

How big is your dose?

About 20g I think that's about the recommended dose for a double with the strega. For clarification I don't mean indentation is the center but the defect on the left of the picture, they are in all my pucks. This morning I ran out of beans and tried to make an espresso with the remainder (which was way too little) and it had the same defect.

#9: Post by HB » June 2nd, 2014, 12:35 pm

Every month or two, someone posts a "puckology" concern; search if you want lots of discussion. I'll repost my most recent response from Dent in the puck, always at the same place:

HB wrote:I'm not into puckology, but I'll play along. I'm skeptical that tamping or uneven water flow is the problem. I would try increasing the headspace by lowering the dose 2 grams and grinding finer. There should be a good nickel's worth of clearance between the top of the puck and the dispersion screen.

Most agree that puckology is between meaningless and nearly meaningless. The only value from your photo is the clear evidence that you're dosing too much, as shown by the sharp screen impression.

June 2nd, 2014, 1:54 pm

Okay I took out the shower screen and cleaned it, the exact same defect now was in another place, then I lowered the dose and the defect disappeared. So the defect in the puck must have been caused by an unevenness is the screen which affected the too larger puck...