I changed my view of this screen: see my last post at or near end re puddling.


E61 open lattice group shower screen stays pretty clean.

I have used this one since Apr 23, so that's 3 weeks.
For me, it stays much more clean than the ones with lots of holes...

Is there any reason why this design should not be used? maybe as it turns out...

Do you normally have problems with your screen getting dirty? I use this one: http://www.espressoparts.com/EPF_228N and I've never had any problems. I backflush with water after every session and with detergent every other week. I only take my screen off once or twice a year to change the gasket, and it has always looked just as clean and shiny as it was when it was new.

Functionally, I don't think there are any differences between the various screen designs.

We've been selling both for a while now
and used them as well on couple of my own machines, I have to agree,
the "new Style" which is the first picture (it is actually refer by manufactures in Italy has "easy cleaning")
it is true, after backflushing the new style has less coffee residues left behind on the outer inside edge then the older style,
BUT the new style as a welded edge at the bottom, that if you are not aware of it could get damaged while prying to pull it out an e-61 group especially if is not done often or is not lubed after re-installing it

Frank - yes, I find they do get dirty and need attention about once a month as it affects flavor. Bleah!

Stefano - yep! you're right! gotta be careful of that!!!

I am now noticing what I will call the effect of "puddling" after a pull - remove pf and look at top of puck - like water mostly drips on puck near center. So will put in "old style" group screen and see...


Yeah, using the old style with lots-of-holes, the pattern on the top of the puck looks like gentle rainfall evenly over the whole surface. Boy did I miss that one!!!

completely irrelevant

Certainly useful knowledge for me!!

I observed that the puddling and emphasis in dropping water near the center was causing a pothole perhaps 1/3 the thickness of the puck.......

Kristi wrote:puddling and emphasis in dropping water near the center causes a pothole perhaps 1/3 the thickness of the puck.

Puckology aside for a moment, have you noted a taste difference? If so, what?

If you want to test whether the difference is real, have an accomplice put in the standard shower screen or the lattice shower screen without your knowing which one is installed. Pull shots and focus only on the taste for two days. Then have the accomplice switch them. Repeat for two days. Then have the accomplice randomly pick which to use for the third and fourth round. If you can correctly identify the screen based on taste, that's evidence against Ian's assertion that it's irrelevant. Otherwise, he's right.

It's worth re-reading Jim's A note on comparison tests to better understand how to assert a difference is significant; it is excerpted below for convenient reference:

another_jim wrote:The basics are really easy, and frequently misunderstood. Suppose you are comparing A & B:

• If A beats B every single time, the pattern becomes obvious in 3 to 4 trials, and pretty much incontrovertible after 7 to 10 trials.
• But suppose A beats B only 11 times out of 20. Then the pattern only becomes obvious in 100 to 200 trials, and requires around 500 to a 1000 to become pretty much incontrovertible.

In other words, the tighter the race between A & B, the more races it takes to say for certain which one is better.

"Pretty much incontrovertible," "saying for certain," "beyond all reasonable doubt," ... statisticians have a phrase that means the same thing ... "a statistically significant result." This does not mean the difference between A & B is big, it means enough trials have been run to say the difference, whatever it may be, exists beyond reasonable doubt.

Kristi wrote:Certainly useful knowledge for me!!

I observed that the puddling and emphasis in dropping water near the center was causing a pothole perhaps 1/3 the thickness of the puck.......

I do not have a need for you to believe as I do. I mean no offense, and I take none.
I felt the need to retract my initial positive views on this, based on my subsequent experiments.

<sliding puck back to center for a second>
how the water hits the puck is as important to me as
>having a grinder that produces a fairly consistent grind with a relatively narrow band of particle size,
>distribution method,
>tamping method and tamping surface,
>the particular basket I choose (capacity, width and precision of bottom screen/holes),
>...

Without doing a myriad of blind taste tests, I am able to logically reason that water will pass differently through 7mm of puck, than 10. I base this on lots of experience, on a bunch of different machines, with failed thin pucks - using too small a dose for a particular basket-bottom-width, and getting sprayed in the face with all the sprites if I happen to be using naked at the time.

Just about all my pulls are 9 out of 10 on my yumminess scale.

Yes, I, too, took graduate level sadistics.

Apparently:
'Logic' + puckology > taste + ease of cleaning