Showerscreen difference

[Spironski]

The left one is my old showerscreen, the right one my new. Since I replaced this, I think my taste has gone downwards. Could this have something to do with the difference of these showerscreens, or is it just coincidence, and are other thing in play?

Thanks,
M.

[cafeIKE]

A side view may give more information.
Is there a step at the edge of one and not the other?

At first glance, the new screen would appear to allow more direct flow at the edge of the basket. It might be instructive to stop the shot after a few seconds of infusion and examine the puck.

[Spironski]

I am afraid I already threw away the old one, but I think from the side they looked almost the same, no step. At the time I was surprised that the screens had such different patterns (that's why I took the photo, did I have a bad feeling about it?).
Okay I can do that: stop the infusion after a few seconds. But what should I see, and what would it tell me? I'm using a naked portafilter and have no squirts. Could be that the cone is a little lighter than before, but then again, I was experimenting before with some other coffee also. Now I'm using my (newly bought) "old" coffee again, I feel the taste is not like it used to, it is not as full and creamy. Or is it that it is an old bag?? That is why I asked: I don't know where to begin, and could the shower screen be of influence? Has anybody have experience with this?

Thanks,
Matthijs

[HB]

That is why I asked: I don't know where to begin, and could the shower screen be of influence? Has anybody have experience with this?

It's not impossible, but I doubt it would make a noteworthy difference for the E61 screens. The E61 has a water jet breaker, so the water doesn't enter the dispersion screen with a nice neat pattern like it would for a machine equipped with a diffusion disk (La Spaziale, Elektra, La Cimbali). That is, the E61 screen is more like the screens for many lever machines - it simply prevents coffee grounds from leaving the brew chamber while the water cushion behind the screen builds. The espresso machines I've seen with diffusion blocks have dispersion screens with a very small gap between the two; the area behind the E61 screen is comparatively roomy.

Could be that the cone is a little lighter than before, but then again, I was experimenting before with some other coffee also. Now I'm using my (newly bought) "old" coffee again, I feel the taste is not like it used to, it is not as full and creamy. Or is it that it is an old bag??

The change in coffee is my bet. That's a much more significant change than the size of the holes on an E61 dispersion screen. The hole pattern and size could influence the initial wetting, but once the grouphead is pressurized, their involvement is negligible, especially if you don't updose.

[civ]

Hello:

At the time I was surprised that the screens had such different paterns ...

From what I can see, there is not just a difference in pattern between the screens in the photo but also what seems (to me) to be a considerable difference in both the size and number of holes.

Provided I have counted right, the old screen has 80 holes and the new one has ~120.

Given that every other possible variable remained constant and if they were the same size, that would be an increase in hole surface / flow of almost 50%. Now, if you then take into account that the new screen's perforations appear to be ~ 25% larger, that makes quite a difference in 'screen performance' so to speak.

ie: the new screen is not behaving like the old one. Now you have a lot more water hitting the puck at 'contact' time than before, pre-infusion occurs at a much faster rate.

Now, is this the cause of your difference in taste? I really cannot say, but the screens are not the same, that's for sure.

Hope you sort it out.

Cheers,

CIV

[ira]

ie: the new screen is not behaving like the old one. Now you have a lot more water hitting the puck at 'contact' time than before, pre-infusion occurs at a much faster rate.

I really have no idea what the answer might be, but the likelihood that the holes in either screen are any impediment to the flow of water at the rates encountered while making espresso, would I expect, be close enough to zero that there is no reason to consider area a factor. The biggest factor might be that the edges get wet slightly faster and that would only seem to be true if the screen was hard against the puck.

Ira

[Spironski]

Thanks Dan, I was a little worried about the screen difference, but it seems I shouldn't be. I will start with buying new coffee then!

@ CIV: With "pattern" I was referring to the size and count of the holes also (remember English is not my native tongue ) so what you are saying was what I was thinking!
Of course I don't know if the pump is building up water pressure so fast that it is actually "hitting" the puck. Perhaps the waterflow is so slow that is actually doesn't matter that much how big or how many the holes are...

[cafeIKE]

I am afraid I already threw away the old one, ... Okay I can do that: stop the infusion after a few seconds. But But what should I see, and what would it tell me?

My thought was to compare the puck infusion.

When updosing, the profile of the shower screen / tamper has an effect on when and how the puck hits the screen.

[Spironski]

My grind is very fluffy, so I do a stockfleth-like thing (a little), then tap the portafilter a few times on the tabletop to settle the grind, and do a 20+ lb tamp with a american curve tamper. That has worked for the past few months, and I don't see a dent in my puck that way, I don't overfill.

The biggest factor might be that the edges get wet slightly faster and that would only seem to be true if the screen was hard against the puck.

But even if I was overfilling, wetting the edges more then before wouldn't be a bad thing, would it?

The more I listen to you guys, and the more I think of it, the more I think I was sold old bags of coffee. I hope it is as simple as that!

[denniskeating]

Hello,
I purchased an extra shower screen for my E61. My stock one was without the button in the middle and has a step at the side edge.The replacement with center button is .020" shorter ,and the puck surface is also flatter, not as much dome. I noticed the replacement one gave more headspace for the puck to swell.
Maybe that is why you notice a difference. The side view would tell you more.
Dennis