@"DavecUK"#1 - This is what I see after every shot during the last weeks. The beans were Coffee Compass - 4 bags and Clumpsy Goat Peru. The CC beans were rested for 2 weeks; the CG’s for 1 month (they had a month old beans). So, freshness can’t be a reason; all are medium dark to the darker side. I wonder what could be the reason. I tried grinding finer and coarser as well. They did not help. The pour remained faster often lasting 18s-19s. It did not channel and I don’t see any obvious signs of issues with the spent puck. I have used a lot of medium-dark beans from Extract Coffee with similar testing period. They were ok. https://i.imgur.com/OSu8NUH.jpg Edit: I am not sure how the images are added here. Clicking the “add an image” creates a https:// link.

Unless you use a service with direct image linking. In addition the image you have linked above expires 2 January, so after that date people will get a 404 image not found link. I use various image services that are completely free and unlimited **Imgur, is one of the most famous** and there is Imgbb which is a bit flaky. **Below is your image via imgur.** I simply downloaded it via your link above, and uploaded it to imgur, clicked "grab link" and simply pasted the link here. **You don't need to use the add image button (which I think is pointless)** at all, just paste the link straight here. https://imgur.com/a/5Mg4385 I notice you're an apple user which means the video which also came downloaded with the image, is in HEIC format and I couldn't play it. Note: I didn't make your image public on imgur, so if you click on it you won't see it on their platform.

Below is what I shared with @"LMSC"#16 via PAM, and hope others will weigh in also: "What you showed in your picture happens to me with every shot since Day 1. I thought about it a lot but think I know what it is, but the thought it is strange and possibly harmful never crossed my mind. My guess – based only a wild guess – is that that is the remainder of unextracted oils from the beans. I am religious about ratios – 18 in 35 out. What follows 35 is definitely NOT the end of the extraction, just possibly not the most ideal as Dave referred on a few occasion in his videos. If that remainder all got into the cup, the ratio is just different. I tasted what went into the cup after 35 and it’s watered down and much lower in flavor, but not god awful offensive. Even if I wait until all the dreads came out and tasted it, it’s only like a mild _cup_ of restaurant coffee – sure it’s sour and pissy, but that’s why ratios gained a following. My suggestion is that you try the entirely of what comes after you pushed the main pull, and let it come to a stop on its own. Then you can judge for yourself how much damage it would do to your drink. 35g is the perfect amount of espresso for me and my wife’s cappuccino so I have no desire to venture into that abyss. I did also try to go lower than 18g with my beans and did think it was as good as 18g. So there! That is my uneducated guess."

I think the other thing it "might" be...if the preinfusion pressure is very low, the puck a bit permeable and the preinfusion time short...there "might" still be some air in the group and the piston pushes that air out through the puck. It would be interesting to observe what the pressure is when it's foaming.

Thanks guys! I emailed @"SL01"#p52 : “Interesting thought as the left-over oil of the un-extracted puck never struck me. Makes a perfect sense as I pull the cup out at a 6 bar pressure, which gives me a consistent 43g-45g. It the continues for another 10-15g of bitter and sour coffee, which I would call as secondary and tertiary extractions. I did try this route and I didn’t like it. I also pull the cup at 7 bar, which gives me about 36g as my wife always drinks milk-based coffee. My concern was why the foam, as I have been thinking some thing was wrong with our beans or the puck prep. Thanks for letting me know the oil side, which I should have known as the beans skews to the darker side.” @"DavecUK"#p54 thinking may also be correct as well. The PI pressure normally hits 1 bar and it is very rare it goes to 1.5. I have been thinking of raising it but never found time to do it. I now have an excuse to increase the default pressure to troubleshoot the foam. Unless I stamp on the puck, which I don’t, the beads on the screen appear in 4-5s. After gently releasing the lever, the bar pressure is >10.5. I will also observe the bar pressure when the foam forms and report tomorrow.

Gentlemen, I must be seeing double - first on PM, and now on the forum! My PI is between 2 and 2.5 PSI for about 10 seconds - the time it takes for the Acaia to read the drips into the cup. I am running on all original factory settings except for group and brew temps. Once the lever starts going up, the gauges goes to exactly 11psi with my current grind and tamp. That foam loom has always been there like a bunch bees hanging from the chin of their keeper. This is the reason I think it's simply the unextracted oil content making their way out of the grind. We don't drink light roasts so the foam is part of my norm.

@"SL01"#p58 If I were to time the shot, which I normally for the first few when the bag is opened, the timer starts from the moment the lever is cocked. So, in a sense the PI and the beads appearing on the screen are much shorter in time. One reason is then certainly the low PI bar pressure and the other is a coarse grind ? Am I grinding too coarse then? The cup is good though. Thx

@"LMSC"#p60 If the cup is good...then it doesn't matter about the foam...it's just a curiosity ![Giphy - Cat Kitten GIF](https://media0.giphy.com/media/hS6KvugVZSAH6/giphy.gif?cid=bb77869f2lnznafbsrnt3tes6sy5vu5u52a1v841t4ma47le&rid=giphy.gif&ct=g)

@"LMSC"#16 My routine involves the Acaia scale. I tare the cup, then watch for 35g to push, not so much the pressure or time. In the end, it's how much coffee gets in my mouth and how it tastes.

@"DavecUK"#p62 I did increase the bar pressure, which now hits 1.5 - 2.0. 1. There is no change in timing (4-5s) as far as the the first few drops are concerned. 2. As @"SL01"#p63 noted, the bee hive does appear. It forms at the end of the shot, 0 bar pressure, after all the tertiary extractions have been collected on the rubbish tray. It takes a few seconds for the hive to form after a full extraction. A few drops of coffee typically falls on the tray. 3. The coffee is a little bitter now after adjusting the PI. I’m at 1.5 turns on JX Pro. I didn’t bother timing as I cut the shots at 6 and 7 for self and my wife respectively. Perhaps, I will loosen the grind a bit or cut the shot earlier. Thx

@"LMSC"#p90 How long is the shot taking in total?

Foam after a shot

LMSC

SL01 Thank you.

We all have different expectations, experiences and taste buds; still the Evo oozes quality espresso. 😊

John_Yossarian

LMSC Like said by others 17 s is on the fast-ish side of extraction.

I suspect that getting a bit finer grind can help bringing it into the 25 seconds domain. Just a thought.

On the foam, I do not think it is an oil issue as oils rather kill the foam instead of producing it. All antifoam formulations are based on silicone oils and silica particles. I wondered whether if you have done backflush with some actives something has been left behind, something surface active.

Another reason might be some proteins extracted from the coffee beans that can serve as foam stabiliser.

I have seen, although very rarely, a bit wee of foam to form at the bottom of the basket but never of that size.

LMSC

John_Yossarian Unlike the E61 machines, there is no need to don’t back flush the Evo. So, that’s ruled out. If you are certain, oil can’t be the reason, I can’t think of anything other than the excessively degassed beans / stale beans - a month old when it was delivered.

Coffee is good to drink. So, I’m going to stop the analytical curiosity and enjoy the espresso. Thx for chipping in.

I am going to grind finer and see how I get on.

John_Yossarian

LMSC I have totally forgotten that you had Leva. For the oils I am absolutely certain, I work with foams so I have come across oils.

Today I will open my bag from Goats Coffee and will report back the result. I might find similar foamy situation 😃

LMSC

John_Yossarian The same has been happening for 2 weeks. All four coffee compass bags had this; these bags had roast dates 10 before they arrived. All of them are medium-dark to dark beans.

Let me know how it goes. 😊

LMSC

Tightened the grind a bit. 18g : 36.2g : 22s. It’s as usual a good cup. Will go finer and see.

John_Yossarian

LMSC you are getting there 😃

LMSC

John_Yossarian Did you open CG’s bag? Which one of them is it ? What happened? Thx

John_Yossarian

LMSC I did open the Peruvian, same as you. I wrongly thought that I had bought the Ethiopian beans.

I have got very nice shot, more nutty than sweet. The shot I got was 17 g/38g for 41 seconds.

I got quite good crema so I do not think the beans are too old.

Have you managed to get longer shots by adjusting the grind?

LMSC

John_Yossarian I did, the one took 45s. There are no issues with channelling, notes, taste, etc. I assume your’s is also the same batch number as mine. The Evo always gives you a nice shot. The nutty and caramel become pronounced when you cut with milk. The bitterness, not medicine bitter, increases as the shot time increase. May be, it’s the caramel taste.

I do think at 45s, there are signs of an uneven extraction with a bit of black ring around the sides walls - see an example. Sorry, I broke the puck while getting it out of the basket.

The grinder is JX Pro; It can grind very fine and is capable of chocking the Evo.

My temps are 92C and 99C.

Foam, it’s there. I have stopped paying attention. I don’t buy their claim the beans is a medium roast. It’s a medium dark/dark category. Perhaps, this roast isn’t for me. 😊

Re-the roast date, they emailed the batch 311006 was roasted on 03/11/2021. A month old, when arrived. It’s what it is. We learn from these experiences and move on. 😊

Thx

John_Yossarian

LMSC Mine looked OK, please see the picture.

I have stopped adding milk to my drinks I usually do when I am out and reduce the risk of disappointment by ordering a cappuccino :).

I had some negative experience with Stirling Coffee, they sent me a pack on discount that was a blend of different roast batches, from light through medium to dark roast, one can tell by just looking at the eclectic mix of beans. I will never buy from them.

Anyway, I would classify the Peruvian beans to be medium roast at best. My temperature is at 94 deg C.

Enjoy the Leva :). I can only mock it by using a profile :

LMSC

John_Yossarian Thx

18g:45g:45s

oztayls

I’ll weigh in with my thoughts. I’m thinking this could be an issue with the solenoid valve or the drain valve if an E61 group head. They may require servicing. Ordinarily, if the drain valve or solenoid valve are working well and are clean, free of build-up, this should not happen as the vacuum would remove it. Service/clean whatever component you have and it shouldn’t happen. Let us know!

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