Hi guys,

recently I've noticed a strange thing happening during pretty much all extractions on my Elektra. This is mostly the effect of comparison between what I see on my machine and various vids of naked extractions and might be the cause of most of my problems with espresso. Just to clarify, this is not only a visual problem, to be honest if the coffee tastes good I wouldn't worry about how it looks like, but sadly it's the opposite, coffee tastes quite bad and has been like this for quite a while. Now I'm not sure this is actually an issue, it might be the coffee I'm using or the way I'm packing it in the basket, so it would be nice if you could check on your own rigs and reply if it's the same or not.

Before I go into the details I wanted to note that yes I'm using fresh coffee, I've tried various ages, super fresh to two weeks old, various doses, various tamp forces, various tamp/distribution techniques, various pressures, various temperatures, various grind settings. First I thought it might be the pump, which was a FOT model with a very high water debit, but after switching to the TMFR, which has a much lower debit, the problem is still there. I've tried various fixes and mods on the machine itself and nothing seems to work, so I'm starting to suspect the grinder which I've been using for quite a while now. As it's a Mazzer Major I doubt it's the burrs as those can take 10 times the amount of beans I grind on it, but on the other hand it's been a while since I've changed them, definitely more than a year ago. Still my average weekly consumption is somewhere around 300g, which gives 1.0-1.2kg per month, so assuming I had the burrs for 1.5year it gives around 20kg, probably nothing compared to what the burrs can take. I never had a problem with rocks or other hard matter in the burr chamber, so the burrs should be damage free.

As I already mentioned in the profiling topic the main problem I'm getting is drippy extractions. Instead of getting a nice cone/stream after a few seconds from the moment the beading starts, the coffee simply drips for a long time and after the stream finally forms it takes only a few seconds for it to go blond. If I grind coarser the stream of course forms properly, but the whole thing blonds even faster and the shot is too fast, with the fine grind the time might be right but the volume is way below normal values, usually less than 20-30ml from a double. Dunno why this happens but it happens with pretty much every coffee I've used and I'm curious if it's cause by too much fines? It's a known fact that too little fines will not work for espresso, but what about too much fines? if that's the case would old worn out burrs cause this? another suspect on the list is preinfusion which normally doesn't happen on the Elektra. I will try to test this today, swapping the smaller Keihin jet with the original from the Elektra.

As usual any and all feedback is welcome.

Regards,
dsc.

dsc wrote:... Dunno why this happens but it happens with pretty much every coffee I've used and I'm curious if it's cause by too much fines? It's a known fact that too little fines will not work for espresso, but what about too much fines?

Too much fines would have been my guess. Don't know if wear of the burr results in an increase of fines? Nor how it would contribute to your condition.

I also was getting something similar (drippy pour with very late cone) last summer (high humidity) with high dose (17-18g) of very fresh coffee and a heavy tamp. You may recognise something commun with your current set-up, although you are mentionning that you have varied pretty much all these parameters, other than humidity.

I just thought of something; Have you check the pump pressure and also maybe the main line pressure? A low pressure may also result in what you are describing... Just a shot at it!

Hi Tom, I was wondering if you have a PF pressure gauge with a needle valve? I was wondering what you water flow volume is for 30 Sec at your standard pump pressure? If your flow restriction into the head is to high your pump and transducer/pressure gauge on the pump side may be much higher than the true pressure above the coffee bed.

Just a thought.
-Cecil

I think Tom's gauge is mounted right above the dispersion block; it should be measuring about as accurately as a Scace 2 from there, assuming the gauge is fully accurate itself. I don't think he has any pressure drop to worry about.

And this is a problem how? Are you entering an espresso porn contest or drinking the espresso?

I believe what you see early in the shot, short versus long delays, prolonged dripping versus prompt steaming, is pretty much irrelevant to the taste and mouthfeel of the shot. When naked PFs came out, we could see the results of puck melt downs, and this is very valuable. But, providing the puck stays integral, most of the other naked PF visual clues are a meaningless distraction.

I think the major next diagnostic step, doable with a naked or clothed PF, is to check the stream about two thirds of the way through the shot. If it's gushing too fast or dripping too slow, but the color is still OK, then you need to mildly adjust the dose/grind combination (for this correction, it's not about which one to adjust, but to get the right pair of settings).

If you are blonding early, and the flow turns to a gush, the best fix is to up the dose a good deal, and not to readjust or only slightly readjust the grind. If you are running a coffee that likes low doses, or you are already at the upper limit of your dosing, you'll need to change coffee or baskets (or go to pressure profiling). The other alternative is to rescale the shot, going much more ristretto in volume, slower in flow, and finer in grind. The taste will let you know which alternative is more likely to work.

On the other hand, I find all the ultra-high tech gadgetry, chasing after mostly imaginary and cosmetic problems, enormously diverting. So if there is a high tech solution, please ignore my suggestions. Have we explored f-stops for basket bottoms yet? Why not start shots at F2.8, and stop down to F32 by the shot's end? That could keep the taste in focus.

dsc wrote:...Just to clarify, this is not only a visual problem, to be honest if the coffee tastes good I wouldn't worry about how it looks like, but sadly it's the opposite, coffee tastes quite bad and has been like this for quite a while. Now I'm not sure this is actually an issue, it might be the coffee I'm using or the way I'm packing it in the basket, so it would be nice if you could check on your own rigs and reply if it's the same or not.

Jim, before going on a rant about espresso porn and the fact that... well you wrote it so you know, please read what the OP actually wrote. It's not the look it's the taste that is the problem. The look is only a description to help us help him!

Jim, I think your frustration with the focus on visual cues is maybe a slight overreaction against the espresso-porno-world: while too much is usually made of visual clues, I don't think they're necessarily useless except when they show you 'meltdowns.' I think Tom's associating his visual 'anomalies' (large flow differential from start to finish and early blonding) with poor espressos, and I think he has a reasonably healthy skepticism on whether it's the cause or not:

dsc wrote:Just to clarify, this is not only a visual problem, to be honest if the coffee tastes good I wouldn't worry about how it looks like, but sadly it's the opposite, coffee tastes quite bad and has been like this for quite a while. Now I'm not sure this is actually an issue, it might be the coffee I'm using or the way I'm packing it in the basket, so it would be nice if you could check on your own rigs and reply if it's the same or not.

Still, Tom, I'd say that why you give a lot of technical details, One key thing that I miss from your description is brew ratios, or more specifically dose sizes and shot volume pairings. For me, reading this—"If I grind coarser the stream of course forms properly, but the whole thing blonds even faster and the shot is too fast, with the fine grind the time might be right but the volume is way below normal values, usually less than 20-30ml from a double."—only gets me so far. Maybe you could walk us through those details and describe the resulting shots. What's wrong with your shots? weak body? Bitter or sour? Any specific flavors that recur a lot?

I'd take Jim's advice in that vein--general descriptions of a shot's flow and specific descriptions of a shot's flavor and mouthfeel will help a lot more than vice versa.

I also agree with his diagnosis of probably dosing somewhat higher. It sounds like your shots are either underdosed or your pressure is too high. Excessively high pressure definitely leads to shots that pull kind of thin (visually) and are bad about channeling and spritzing, with a resulting cup that's often harsh and one-dimensional, at least in my experience. If you're shooting for 9 bars at your point of measure, I'd say don't take that as a mandate from on high--you may like maxing out at 8 bars or even 7.5 a little better. Don't confuse excessive brew pressure with bad burrs; you'll just end up blowing more money on burrs and stuck at square one.

shadowfax wrote:... It sounds like your shots are either underdosed or your pressure is too high. Excessively high pressure definitely leads to shots that pull kind of thin (visually) and are bad about channeling and spritzing, with a resulting cup that's often harsh and one-dimensional, at least in my experience. If you're shooting for 9 bars at your point of measure, I'd say don't take that as a mandate from on high--you may like maxing out at 8 bars or even 7.5 a little better.

From Tom description I would have thought low pressure... There is no mention of chanelling or spritzer plus when he grinds coarser the cone forms better...

Underdosing might be a contributor but he also mentions trying various doses.

Finally, Tom, I just noticed that your machione has adjustable pre-infusion. Yet there is no mention of it in your text. How long is the pre-infusion for and at what pressure. Have you tried varying it. Just troubleshooting.

Whale wrote:Jim, before going on a rant about espresso porn and the fact that... well you wrote it so you know, please read what the OP actually wrote. It's not the look it's the taste that is the problem. The look is only a description to help us help him!

I'm so happy to have a watchdog, and one who can roll his eyes yet. But you're right, I should have asked whether there is at least a correlation between the taste and flow.

Instead, what I read was that in the midst of doing extensive modifications on his pump and brew path, the shot's taste has been doing poorly, and the early flow has gone wonky. Given all the modding dsc has been doing, the trigger for the poor taste could be a laundry list of proximate and distal causes, or something unrelated. If these mods have left the machine in an unusable state, I cannot help; this is a repair problem, not a technique one.

But if the mods have just changed the brewing characteristics of the machine, so that adjustments have to made to technique, then I and the more experienced members can help; especially if the peanut gallery of self-appointed watchdogs would kindly make a bit less noise.

The way to correct espresso problems is to taste analytically and make corrections accordingly. In this case, is the taste and mouth feel thin or heavy and bitter sweet? You can then learn for yourself how to correct these by deliberately and consistently reproducing the same taste faults:

• Dose lower and lower, and grind finer and finer to maintain shot times and extraction ratios. Eventually, the flow will get drippy and the shot will be thin in both taste and mouthfeel. This is a result of a sort half channeling. Small density differences in the cake create variations in the flow, but without the puck cracking. The results is that you get overextracted and dilute shots made with only a fraction of the coffee. If this is the taste problem, you've gone below the lower limit on dose for that basket -- dose a good deal higher, and grind coarser (or change baskets, or use WDT to improve on the usual density variations in the puck).
• Keep the dose the same, and grind finer and finer. You will again have drippy flow, but this time the shots will taste excessively bitter-sweet, have heavy mouth feel and thinnish dark crema -- it's an overly ristretto shot. In this case the cure is to simply grind coarser and run a longer volume. You can change dose as you please, since you are not at the basket's limits

If you can dose and grind in a way that consistently reproduces the taste and flow problems you're having, the cure becomes self evident. If it's happening at all or almost all doses and grinds, your mods may be creating the problem, since even dull burrs would not do this.

another_jim wrote:... But if the mods have just changed the brewing characteristics of the machine, so that adjustments have to made to technique, then I and the more experienced members can help; especially if the peanut gallery of self-appointed watchdogs would kindly make a bit less noise.

Sorry you feel that way.