Disappearing crema, you too?

[mstefanakos]

Wanted to get the groups thoughts on a vexing issue.
The crema on the espresso from my S1 Vivaldi seems to effervesce and disappear very quickly. I know you are thinking my beans are too fresh and they just havn't finished off gasing. Yes, I use the best fresh beans.
Roasted by Sweet Maria

[Weska]

Very puzzling. I can't say that I've encountered that problem.

However, for the sake of clarity, can you say to what extent exactly the crema disappears? My crema is abundant, but after a minute it will collapse to about half the original volume (which I think is OK and just the result of cooling). If your crema really leaves altogether so that your espresso looks like a cup of drip, then that's unusual.

Also, have you observed in a transparent container how much crema is being produced originally? Losing half of not-much-to-start-with might leave you cremaless. For the sake of reference, in my shot glass there is nearly total crema during the pull. Within a few seconds after the shot is done, that crema boils to the surface so that about a third of the volume is crema. That crema collapses (with cooling, as I believe) over the next minute.

How does yours go?

[Niko]

Only thing that comes to mind is pump pressure.
It's still a big head-scratcher though... :?

Are you using a Bottomless PF? Crema seems to disappear quicker from them compared to spouted.

[coffeeowl]

I can repeat what Weska said, however, my shots don't last that long :D I'll drink it as soon as the all-crema shot transforms to half-or-third-crema-surface.
I suggest you post a few pictures (with a time reference).

[hlsheppard]

I don't think you mentioned machine cleanliness... I know you spoke of soap residue on your cups (which is a KLLER).

I know when my crema isn't quite what it should be I do a backflush routine and soak all basket/screen/pf parts in Cafiza.

Old/excessive espresso oils are a killer to crema as well.

[chas]

I concur with Howard. While I haven't noticed this effect with my coffee. I also home brew beer. Soap and other residues that either get into the glass or are already on the glass will kill the head on a beer. I imagine crema on coffee would be the same.

[Richard]

I also home brew beer.

I *knew* there were multiple reasons to like this site.

[Weska]

And I used to be a home brewer in the early days when you bought stuff in somebody's basement or garage.

I had a ball with that, but it's hard enough getting green beans here without trying to find sources for hops, malted barley, yeast...oh, my!

[mstefanakos]

Thanks for all of the input.
I will try and get some photos (in a clear Bodum double walled glass) with time details.
I don't have any real specifics right now, only that the crema on shots from the Pasquini Livia 90 last forever and the shots from the S1 seem to fade very quickly. That's my reference point. And my friend with the brand new VII seems to be having the same experience.
I'll get some more scientific details for the groups consideration post haste.
Other notes:
Chris's coffee dialed in my machine and my friend's too, so I can't imagine the pressure is off.
I am using a bottomless PF.
I clean my machine regularly. Daily blank back flushes (water only, no cleaner), weekly soaking/cleaning of the group components and monthly Cafiza backflushs.
I use a 2 stage water filter.
Stand by for pictures. But, keep talking and thinking about this.
Thanks
M-

[mstefanakos]

Okay....I did a little test this morning.
26 second shot (I like it a little longer).
Full glass of crema at the end.
Guinness effect just like we hope.
Within 60 seconds of shot finishing...just a 1/4" of crema
Within 90 seconds of shot finishing...just 1/8" or crema
2 min and 30 sec after I finished pulling the shot...just a thin layer of crema was all that was left
At 3 min you could see coffee in the center and only a ring of crema was left around the edge.
I took video, will post it on YouTube and then add a link here.
Talk to me team, you are my only hope!

[JohnB]

Are you preserving these shots or drinking them? How long do you need the crema to last? After 90 seconds or less that cup should be empty.

[mstefanakos]

I hear ya.
But, from time to time I:
Set a shot down for a minute.
Make one for my wife and she gets distracted.
Etc, etc.....

I'm not looking for my crema to last all morning.
But, when I compare the crema on my S1 shots to that of ones pulled on my Livia 90...the crema holds up better and longer. Dare I say the Livia delivers better crema.

It's that notion that lead me to the quest for a solution. I can't believe that my dual boiler S1 wonder machine can't run circles around the Livia in all aspects.

So, to sum up, it's not that I want to preserve crema for hours, it's just that if the Livia's crema lasts longer, isn't it by definition more dense and better?

[JohnB]

Since the V2 is my first Espresso machine I have nothing to compare it to but I'd say my crema fades about the same as yours. Of course I could be making the same mistake as you or it could just be normal for these machines. With 233 members you'd think we'd get a little more feedback on questions like these but it seems that only a half dozen like to post.

[Niko]

You didn't mention WATER.
What kind of water are you running through the Livia vs. the Spaz?
This could be the reason why the crema is different.

I know whenever my filters get changed, the water tends to be a little fizzy for days if not weeks, this does affect the espresso and its crema over here on my machines.

[mstefanakos]

Niko,
Thank's for your help on this. Below are the details on the water piece of the puzzle:

1) I use a 2 stage in-line water filter for both the Livia 90 and the S1. In fact, I have used the same water from the same filter with both machines and had consistent results.
Livia - Long crema
S1 - disappearing crema.
To elaborate: I spliced a faucet in-line (after the filter and before it gets to the s1) so I can use use the filtered water for drinking and cooking. I filled a pitcher with the water and used it in the Livia.
2) I have had my water quality tested for hardness and everything else. The water passed all tests with flying colors.
2) The filters are not new and they are fresh enough they don't need to be changed.
4) My friend who lives in a different city and has different (filtered) water is experiencing the same issue as me on her VII.

Thoughts?

[Niko]

Wow, this one certainly is a real head scratcher.
Given the two machines are so different, one has a rotary pump and the other vibratory - you'd think that a simple pressure change might alter the crema output on the machines.
The Livia must be producing smaller bubbles so they take longer to dissipate, whereas the Spaz must be producing larger, more fragile bubbles that break down faster causing the crema to disappear more rapidly. :?

What is the incoming water pressure on the Spaz and what is the manometer reading when idle (on the left)? Mine sits around 1.7 bar on average.

[mstefanakos]

I don't know what the incoming water pressure is. It's city water if that helps.
Also, my machine is only a lowly S1. Net net...I only have the single gauge. My single gauge slowly fluctuates between .9 and 1.1 bars.
Also, I only have a bottomless portafilter, so I can't make a pressure gauge. Chris's coffee set the pressure and tested the machine last spring, so I can't imagine pressure is an issue.

But, if anyone has a portafilter pressure gauge they'd be willing to loan me, I could test it?

[woodchuck]

Just a quick question on the pfs used. Are you using a bottomless on both machines? The naked pfs will produce a different head than the spouted filters.

Ian

[mstefanakos]

Bottomless on both.

[JohnB]

Your water pressure will change your rotary pump pressure if its different from what the pump was set on. CC sets pump pressure using 30psi line pressure in their shop. You might want to find out what your line pressure is.

[Niko]

I'm not a betting man but I'd say the Spaz isn't pumping at the same exact pressure as the Livia. Not saying that the S1 is set wrong nor the Livia - just being different pressures will result in different cups.

[Weska]

OK, mfstefanakos, I will add my findings.

Little as I like to leave an espresso sitting around while I could be drinking it at a scalding temperature, I put a double to the test tonight. It was nominal at 24 seconds for a double from 13.5 grams of Moka Kadir not quite two days old (and therefore fairly gassy and inclined to exaggerated crema).

Anyhow, it was almost entirely sizzling crema during the pull. (I can see it through my double-walled Bodum shotglass.) After the pull it settled out to about a generous centimeter of crema (say slightly under half an inch) well before the first minute was up. After a second minute undisturbed, this had collapsed to maybe half its original volume. After a third minute, it was a very pronounced meniscus shape but nowhere less than an eighth of an inch. At the fourth minute it was essentially the same as at the third.

In four minutes I never saw my crema shrink away from the surface altogether. Still good to drink.

It really does suggest impurities are at work somehow in your machine and your friend's. (But how likely is that?) My water is rather hard but softened and filtered before it gets to the Vivaldi.

[mstefanakos]

Okay....new data point.
A very generous and trusting LaSpaziale owner sent/lent me his portafilter pressure gauge (I have an S1, so I don't have the dual gauge).
On my machine the gauge reads 100 to 105 PSI. That's only 7.5 bars.
I'm going to pump up the pressure and see what effect that has.
But, let me know your thoughts based on this latest data.

If anyone out there has ever adjusted the "Group Pressure" and has advice, let me know. My plan is to follow the instructions in the S1 owners manual. But, ping me with any pit falls of suggestions.

Also, the manual says 8.2 - 9.0 bars. What is the sweet spot IYHO?

Thanks
M-

[Niko]

The machines are adjusted to 9 bars from Chris' Coffee before shipping.
Mine fires at 9 bars and the crema does not disappear.

[JohnB]

Most users seem to be between 8.5-9 bar. At 7.5 you are definitely way out of the ideal range. Try 9 & back it down if you aren't happy. This covers what you need to do: http://www.rimpo.org/s1/S1_Expansion.html

[mstefanakos]

Eureka!!!!
Thanks everyone. 9 bars does the trick. I have made 8+ shots since the adjustment and BAM...delicious. And the crema stays a long, long time.
Adjusting the pressure to 9 bars is VERY EASY. If you ever need to make this adjustment, have no fear, it's super easy.

Thanks again for everyone's input and brain power!

[Niko]

I had a feeling it was brew pressure all this time...

[coffeeowl]

Just in case:
a reading and watching.