Consistent astringency after 20 yrs of effortless decent results

Beginner and pro baristas share tips and tricks for making espresso.
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#1: Post by skeddy »

For years I made espresso the same way, with little attention to detail. Results were inconsistent, but mostly drinkable, and often good. Within the past year my espresso became undrinkable: consistently bad tasting in a way that is new to me.

How did a setup that produced satisfactory results for so long, and that was so tolerant of variation, suddenly start producing consistently undrinkable espresso?


I've had a Rancilio Silvia V1 for ~20 years. In 2017 I added a Rancilio Rocky grinder. My procedure was as follows. Buy the espresso roast from any hipster coffee shop in San Francisco, e.g. Ritual or Equator or Reveille. (I did not care for Peets nor Blue Bottle.) After the boiler heats up, run 10 seconds of water through the portafilter. Dose into portafilter, overfilling it, then skim portafilter with something flat to remove excess, resulting in a ~consistent dosage. Knock the side of the portafilter to settle the grounds. Tamp by hand. Brew, counting slowly to 15.

I never used a scale or a clock. What I found mattered to my palate was to buy coffee that had been recently roasted, and to adjust my grinder fine enough to keep the rate of flow down.

Things mostly tasted good, so I never strove for greater consistency. The changes over this period were few: I moved house and so changed coffee, I replaced a gasket, I learned to backflush the machine with a blind filter and detergent. All seemed well.


6-12 months ago my espresso started tasting terrible. If I drink it it upsets my stomach. It coats my mouth, makes me pucker, and it is very difficult to wash the taste out. "Astringent" or "tannic" feel like good words, and "bitter" and "sour" don't feel wrong either. (Sorry, I know bitter and sour are supposed to be different things, but I'm not sure I can tell the difference.) A lot of the description in this post sounded familiar: Troubleshooting "tannic" espresso

I've perturbed a lot of things but this bad taste persists. And it's new to me: I've never run into this particular bad taste before.


I moved to Austin in 2021. San Francisco's water is often rainwater; Austin's water is (as I understand it) ground water filtered through mostly limestone?

A year later I had the boiler replaced, because it had developed a leak. The new boiler has a replaceable heating element, whereas the original boiler did not. Before the boiler replacement, the pump would make noise all the way through backflushing. But after the replacement, the pump would quiet down to a low hum after the first few few seconds of backflushing. This is apparently normal-but it is a change.

The onset of the problem was somewhere in the 6 months following the boiler replacement. But not, I think, immediately after?


As should be plain from the above, I've been satisfied for a long time with imprecise but drinkable results, and I'd be very happy just to get back there. I don't aspire to big improvements-I just want to figure out what changed and fix it!

Here are all the hypotheses I could come up with:
  • A change in the beans? I've tried at least 3 different vendors.
  • The grinder? I cleaned it thoroughly, replaced the burrs, and even shimmed them with foil to be a little more even. And of course I've varied the grind.
  • A change in temperature? I've experimented with higher (by switching on the steam temperature for a little while) and lower (by letting the machine cool down).
  • A change in the water? I don't see an obvious change in hardness in Austin Water's reports. But I could experiment with making my own water.
  • A change in pressure? I'm not sure how to test this.
  • Scale? I've done a round of Dezcal. I could do another.
  • A change in me? Possible, but everything else takes the same.
I'd be very grateful for any hypotheses or suggestions for experiments. I do not want to buy stuff if I can possibly avoid it. Thanks in advance!

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#2: Post by bostonbuzz »

As a sanity check I usually get the "medium" roast from a third wave shop and try and get a good pull with that.

The main thing I can think of is your pump and OPV. Vibe pumps can have issues creep up, as can OPVs. If you are pulling shots at 15 bar, for example, because your OPV is clogged then you will struggle to pull nice shots. Not so much of an issue if it's lower pressure.

Is there a brew pressure gauge on your Silvia?
LMWDP #353

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#3: Post by atao »

If this were me, I'd try to take as many variables out first and then gradually add them in.

If you had a local roaster where you like the coffee, then that seems like a good starting point.

I'd start by cupping the coffee at home to take the espresso machine out of the equation. That could confirm whether the water or grinder are responsible.

If those taste reasonable, then I might suggest starting with a turbo shot, like 18 in, 50 out in 20sec. This is a much more forgiving shot style than a tight one.

If you have the ability to measure temperature, that'd be good to do as well.

If all of those tests deliver good coffee, I'd have to agree with the previous poster that perhaps it's something pump related

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#4: Post by lagoon »

Do you get the same astringency when drinking coffee prepared elsewhere? Eg at a good local cafe?

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#5: Post by mgwolf »

Did you by chance have Covid? That can dramatically affect your sense of smell/taste.

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#6: Post by Shantastic »

Hey, were you able to sort anything out, or are you still having issues? Do you regularly remove and clean your shower screen? Have you tried a new water recipe? I don't envy your situation but I find the problem interesting to have just started out of seemingly nowhere

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#7: Post by NoUBrew »

I just ran into a similar issue with my machine (that I haven't actually solved) but I believe the issue is that there is some kind of junk growing in the machine. Either algae or bacteria.

A couple of key similarities: my espresso tasted awful in a way that I could not link to bad technique. I called it "rancid". It upset my stomach when I drank it.

I did get in touch with WLL support and they seemed to be in agreement about some kind of microbes in the machine.

Pull some hoses off near the pump and/or boilers and see if you can detect any strange odors. Mine smelled "fish tank-y".

skeddy (original poster)
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#8: Post by skeddy (original poster) »

Thanks to all for your suggestions. I thought hard about all of them, but in the end the thing that worked was buying different beans. This result makes me crazy, because I had certainly tried it before, but it seems to be true.

The beans I'm buying now, which taste fine, are Red Bird Espresso, from Red Bird Coffee in Montana.

My regular coffee shop produces espresso that tastes OK using (I think?) the very same beans that, for me, yield the nasty and astringent results that I had been trying to fix. This was true over at least a dozen bags of coffee, over a period of months. There was one other vendor whose coffee I tried several times, to no better results. I'm pretty sure I tried a third and a fourth alternative too, but since my notes from that time are spottier, I don't want to swear to it.

I have no idea why things are better with the new beans, and I'm tempted to buy another bag of the old beans just to rule out some other simultaneous change. I'm not sure it's worth $20 to me to find out, but I'll follow up if I do.

I'm sorry my story is so unsatisfying, but I did want to include the resolution, such as it is, for anybody that may find themselves in a similar situation.

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#9: Post by Rustic39 »

I'm not at all surprised by your findings. While I don't live near a plethora of local roasters, those I do have within a hundred miles, haven't provided me with a satisfactory product for espresso. I probably have similar tastes to your's if you like Red Bird. I ultimately resorted to roasting my own, because of the costs and inefficiency of trying to schedule new orders on line to deliver when I "might" run out. I'm now satisfied with trying so coffees from around the world, freshly roasted to my liking and ready to go when I am.

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#10: Post by Jasonian »

Glad you got it sorted! I was about to chime in and say "It's the coffee!"

If the drying phase during the roast is incomplete, you get astringency. There's not a thing you can do about it, except to toss the bag, and buy a different coffee.
"Pro" coffee roaster. Ex barista trainer, competitor, consultant.