Frustration pulling a good shot, back flush cleaning issue?

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GooseCA

#1: Post by GooseCA »

Hello all,

Recently have been having a lot of fun pulling shots but now I am getting frustrated. I have the Breville touch, calibrated tamper, bottomless portafilter, grinder baffle (single shots). and using third wave water. Have tried Lavazza Gran Crema plus two other local rosters and fresh beans from Peet's coffee. I am consistent and pulling 18 in / 36 out in 26-30 seconds. Have pulled faster shots and long shots, the majority of the time I am tasting bitter with an aftertaste that lingers. At first, I thought that I am getting the two mixed up. so I did a salami shot and the first shot glass (5 seconds) was extremely sour and tasted horrible. The other glasses were less sour and toward the end, it was just watery but never had any good flavors (forget about sweet or other notes). Always purge the group head before pulling the shot and keep the portafilter/basket clean. I have been pretty meticulous when pulling the shots, checking with the razor tool the depth, cleaning even the grounds from the side, etc. Have watched videos where there is more channeling, the ratio is off and according to the presenter a good tasting shot. After reading the reasons that can cause a bitter shot the cleaning came up, how many shots after do you backflush? With these dialing-in / test shots, I have been attempting, can this be my issue? I am backflushing tomorrow for sure! Any tips for someone new to pull a good-tasting shot?

Thanks!

Nunas
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#2: Post by Nunas »

I back flush with plain water after I've pulled all the espressos. I back flush with chem (Cafiza) about once every two months. I manually clean the removable parts of the group and the water reservoir monthly.

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cafeIKE
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#3: Post by cafeIKE »

36g out in 30s, if timed from pump on and not first drop, is a gusher.
I'm assuming 18g of coffee?
Use less coffee and grind finer.

GooseCA (original poster)

#4: Post by GooseCA (original poster) »

it's with first drop, I am going to do a cleaning today and play with the ratios.

Splunge
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#5: Post by Splunge »

GooseCA wrote:the majority of the time I am tasting bitter with an aftertaste that lingers.
Lingering and bitter suggests stale coffee residue to me.

I pull six to ten shots per day and back flush several times (water only, starting with a PF wiggle to clear loose grounds) after each session. I then jam a jcloth or similar up and slide it around the circumference of the gasket area, burning my fingers in the processs :cry:. If I see any residue on the cloth, I repeat till it comes out clean.

I backflush with detergent generally every Saturday but will often do it sooner if I begin to taste the dreaded "lingering bitterness" (a good description) creeping in by Thursday or Friday. The fact that it hangs on as a bitter but stale aftertaste distinguishes it from bitterness due to over extraction.

While my workspace is often a mess with loose grounds and coffee bags everywhere, I keep my group spotless. It makes a real difference in the cup.
Chris

Nunas
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#6: Post by Nunas »

Splunge wrote:Lingering and bitter suggests stale coffee residue to me. I pull six to ten shots per day and back flush several times (water only, starting with a PF wiggle to clear loose grounds) after each session. I then jam a jcloth or similar up and slide it around the circumference of the gasket area, burning my fingers in the processs :cry:. If I see any residue on the cloth, I repeat till it comes out clean. I backflush with detergent generally every Saturday but will often do it sooner if I begin to taste the dreaded "lingering bitterness" (a good description) creeping in by Thursday or Friday. The fact that it hangs on as a bitter but stale aftertaste distinguishes it from bitterness due to over extraction. While my workspace is often a mess with loose grounds and coffee bags everywhere, I keep my group spotless. It makes a real difference in the cup.
While I generally agree with this description, the part I've emphasized gives me pause. For some machines, like the GS/3, one can clean with chem quite frequently and the machine will hum along happily. For those of us with e61 machines, such a maintenance routine is impractical, unless coupled with more aggressive lubrication of the mechanism. In my previous machines, several of which were not e61, I frequently backflushed with Cafiza. When I got my first e61, a Magister Stella with a Rancilio e61 group, this immediately caused problems. The e61 group requires lubrication of its cam, to keep it moving smoothly and to keep the cam and cam followers from wearing rapidly. Not knowing this, my lever quickly started to become increasingly hard to move, and it began squeaking. Thanks to helpful folks on a forum (maybe this one, maybe CG...I can't recall), I remedied the problem by lubing the cam, only to find that it quickly returned. At this point, not wanting to remove and relube the cam every few weeks, I started backflushing with plain water after every session, manually cleaning the shower screen and dispersion plate (much like Spluge describes), and limiting the use of Cafiza, first to monthly and now to about bimonthly.

Splunge
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#7: Post by Splunge »

For sure, very different with an e61. For the 15 years I had my Vetrano I'd use detergent every two weeks only, adding Dow 111 (which can do weird things to your shots :? ) to the cam less frequently - whenever it'd start to squeak.
I'd also replace the valves annually, with a new cam every few years, but that's not too crazy for a machine running 24/7.

I'm a tinkerer anyway, so don't mind when something wears out that I've already gotten a lot out of.
It's premature, but the group on my 1 year old GS3 has developed a mysterious slow drip - I couldn't be more excited cause now I get to take it apart! :D
Chris