Cimbali Jr = sour everytime, why? - Page 4

Need help with equipment usage or want to share your latest discovery?
Ken Fox

#31: Post by Ken Fox »

SamuraiE wrote:Thanks for your comments, Ken. I am using a pf 20atm gauge to measure group pressure....set to 11 bar....sorry for the confusion.

I suppose the tests were to verify if the machine has a problem with temp drops over a serious of pulls...as my shots tend to get more and more sour as a sessions continues.

PID sounds nice....but with the outrageous prices of parts and service over here I doubt it would be possible.....unless I can convince Jim and his family to suddenly take up surfing and start making annual hops across the world in search of 6 ft. long righthanders.
Well if you are set to 11 bar, you could consider adjusting the rotary pump to read 9 bar; it is a very easy adjustment and the owners manual shows where the screw is located that needs to be turned on the rotary pump. I have no idea if this will make your shots taste better, however.

If I were you I'd set my boiler temperature to around 1.1 bar maximum (or 1.05bar), with mimimum about 0.15 to 0.18 bar lower, depending on how well your pstat functions. If you don't like the end product than I'd be more likely to question the coffee you are using or the way the shots are being made than the equipment itself.

ken

SamuraiE (original poster)

#32: Post by SamuraiE (original poster) »

Hey Ken, I hear you...but I don't have a rotary pump, this is a S1, vibe pump, like your older machine. Shots are sour, thus the temp tests to see if it is a problem with the machine or with....................you know.............me.
I am not worthy!

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HB
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#33: Post by HB »

SamuraiE wrote:Pours were about 8 seconds which gave me 165 ml or 5.5 oz of water....didn't use a pf, just poured straight from the group right into the carton. Wanted to draw less water but didn't realize until too late that I was getting such a high volume. Pulled for about 8 seconds, waited 30 seconds then pulled again, and again, etc. (as per Dan's orders).
Sorry, the extra volume invalidates your results. Even so, what strikes me as unbelievable is that a BLAZING hot boiler setting of 1.6 bar doesn't produce flames pouring out the sides! The evaluation model I tested was set to 0.9 bar when it arrived and I tried settings ranging from 0.7 to 1.3 bar.
SamuraiE wrote:Shots are sour, thus the temp tests to see if it is a problem with the machine or with....................you know.............me.
If you and Ken agree to re-run the test I described above at the same setting (e.g., 0.9 bar) and compare, I would expect them to correlate within a couple degrees, even with the weakness of the "Styrofoam cup" technique. After that, the only remaining logical steps are (a) calling in the expensive service guy, (b) breaking out the tools on a witch hunt.

PS: Did you note the boiler pressure gauge behavior during the test? How long did it take to recover? Normally Junior's heating element will not click on after every extraction, but rather every second or third because of the huge HX.
Dan Kehn

SamuraiE (original poster)

#34: Post by SamuraiE (original poster) »

Dammit Dan! All that work for nothin'! Oh well....Yes, I am an idiot.

Let's see, I wrote to La Cimbali directly and Mr. Carlo Tambussi says the I should set the boiler to 1.2 bar and temp should be 70 C in the cup (geez, I knew that, thanks for nothing). But he does say that all Cimbali products have a standard length injector (so a least we can rule out that). Then he goes on to add that I should call my distributor (ain't got one).

By the way, the heating element did not kick on for every shot as you say, it kicked on every third or fourth.

OK, before I sell my 4-year-old son to pay for the home visit.....I will wait for the variac to arrive and give that a go.

If I try the test again at 90 ml, what temp would be ideal in my cup? 92 C?

Thanks
I am not worthy!

Ken Fox

#35: Post by Ken Fox »

SamuraiE wrote:Hey Ken, I hear you...but I don't have a rotary pump, this is a S1, vibe pump, like your older machine. Shots are sour, thus the temp tests to see if it is a problem with the machine or with....................you know.............me.
Cheer up, there isn't any clearly visible difference in the cup, vibe vs. rotary. The pressure on your vibe machine can be adjusted to produce a steady 9-ish bar. Most probably your machine lacks the silicone tubing needed to run from the nipple of the overpressure valve back into the pourover tank. I would not even try to suggest where you might buy silicone tubing in Japan, but I got mine from Mcmaster Carr in Los Angeles, and attached the tubing to the nipple of the valve with a twist tie. The valve is located just behind the front panel, so to get to it you need to take off both sides of the case and then the 4 screws that hold the front on; none of this is difficult. The OPV likely will need to be adjusted several times over a week in order to get it to adjust and to stay adjusted. Once it seats right, after a few tries, it should stay where you put it. If you aren't now using your OPV, most likely your machine is producing about 14 bar peak pressure with each shot. I don't know if that itself could be producing some of what you are tasting in your shots.

As to using a cup to test temperature, I think that method has so many limitations that I'd be reluctant to base anything on it. I think that if you set your machine to 1.1 bar maximum on the front panel gauge, then flush your group until it stops flashing (and then some), you will eliminate temperature as the cause of your problems. I still don't exactly understand what the problem is, but if there isn't anything obviously defective in your machine (and from what you have written I think there is not), then the fault lies in something else, such as the coffee you are using (which might just not be to your taste, who knows), elements of barista technique as apply to this commercial machine, or something else. This machine is more demanding when it comes to barista technique than your typical home or semi-commercial unit. When I don't distribute the grinds carefully in the PF, for example, there is no getting around it; a sink shot is coming. I am beginning to doubt the problem is in your machine, and perhaps you need to look elsewhere into elements of technique or the beans you are using. If you are using home roast, the fault could be in the roast level or how you get to that roast level. I myself have made every mistake in the book when it comes to roasting so I would not discount that possible cause, either.

ken

SamuraiE (original poster)

#36: Post by SamuraiE (original poster) »

Ken, how quickly you forget....or maybe you just help so many Jr. owners that we all begin to run together in your mind. You gave me all that great group pressure info (plastic tube, as well) several months back. I had the group pressure down to 9 bar and ran the plastic back into the tank for months....worked out great! But for the these tests I decided to raise the group pressure back up to 11 bar.

As for setting the pstat....it was at 0.9 for the longest time, but shots are cool and taste is sour, the more shots I pull the more sour they get, so I cranked the boiler back up to 1.6 bar with the hopes it would increase the temp and get the color of my crema darker than it is. The machine just doesn't seem to get hot enough. As for beans, I have a Hottop and roast Monkey Blend from SM, into 2nd crack. The roast always look great.....so have a hard time talking myself into all of this being bean related. I keep thinking the voltage in my old Japanese house just isn't giving Jr the juice he needs, thus cool, sour shots.

Of course we can't rule out user error.....pf distribution, tamp, etc.

Know you are up to speed on the problems without having to read through the entire thread. Thanks for your comments.

p.s. I wacked off the doser on my Cimbali grinder....it is now doserless....Japanese machine shop made a spout....will let you know how it works out.

Key
I am not worthy!

Ken Fox

#37: Post by Ken Fox » replying to SamuraiE »

Hi Key,

For some reason I have gotten an undeserved reputation as some sort of Cimbali Junior guru; as a result I get frequent emails about Cimbalis (often from people who lurk in forums but never post), and I participate in a couple of forums plus a.c. Unless I know someone personally it becomes very difficult to remember who is who especially when a lot of the questions are similar. And, when you have people who use more than one name (e.g. "Key," "Samura," as but one example) then I really haven't a clue as to whom I'm talking to!

Temperature is temperature regardless of how it is achieved. If your local current is on the low side (and there is variation in household current), but your pstat shows a particular pressure (correllates with temperature), then the temperature you have is the temperature you have. If it takes the heating element in your boiler 25% longer to recover after frothing than mine takes, still, once you get to the temperature/pressure setpoint, you are at that setpoint. And, the thermal mass of a Cimbali Junior is such that you should be able to make a shot or two or three without the (potentially lower) house current having much impact. Sure, if you are making 100 shots per hour, you are going to notice it, but if we are talking about typical domestic usage, I really doubt you would notice it. Of course, you could have a level of current that would be SO LOW that it would damage the pump, but I don't think you have observed that.

Have you considered the possibility that you got a bad batch of green beans? I have received bad beans before without having changed suppliers. There was a celebrated incident of an online merchant selling Monsooned Malabar that was labelled as Malabar Gold. sh** happens. That would be the line of thought that I would pursue because I sincerely doubt that a variac will help you one way or the other.

Good luck!

ken

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#38: Post by HB »

SamuraiE wrote:If I try the test again at 90 ml, what temp would be ideal in my cup? 92 C?
Closer to 94C would be better. BTW, I agree with Ken's thinking that the blend or technique are at fault. When I start with an evaluation, I always use a standard blend (e.g., Intelligentsia's Black Cat) and bottomless portafilter to diagnose problems early on. You might switch to a pre-roasted blend from a reliable source to eliminate one more variable.
Dan Kehn

SamuraiE (original poster)

#39: Post by SamuraiE (original poster) »

Dan, Others, I got it! I did it! Espresso Nirvana! Tonight I got the temp bug figured out!

The Key (no pun intended) was Dan's advice of 94 C in the cup. I began really working all the angles on how to get that temp in the cup.

Using just a shot glass, a pf (without its basket) and a dig temp thingie, I started flushing away. Here is what I found out. Firstly, the variac didn't seem to play much of a role in any of this (for those keeping score at home that makes it: Dan- 1...Key- 0), my espresso machine repeatedly gave me a standard 88 C in my shot glass after long idle periods (anything over 3 mins down time). I next flushed 60 ml at 30 second intervals and watched the temp rise steadily until it reached 93.4 C after the 5th flush.

Next, I tried 60 ml flushes at 15 second intervals......after the 5 flush the temp reached 94.5 C in the shot glass.

So.....after long idle periods the machine is cool, and the flushes serve to warm it up (but you knew that already, right?). Lots of things to report:

It seems important to wait the 15 seconds after the 60 ml flush, when I tried pulling quicker than 15 seconds (say at 5 or 10 seconds after the 5th flush) the temp was always low again....around 92.5 C.

Also, it takes 5 flushes to bring the machine up to 94 C.....4 flushes won't do it (93.5 C).....only after 5 flushes.

So to pull a shot, 5 flushes of 60 ml at 15 second intervals....lock and load the machine and 15 seconds after flush #5 pull the real shot. It worked perfectly! NO SOURNESS AT ALL. The shot looked terrific out of the pf and tasted even better.

Remember this is a La Cimbali M21 S1 pourover model made to run on Japanese specs of 100 volts.

Finally, another big factor in all of this was that I finally finished my K.A.T. (Key Auto Tamper) this week. It is a Japanese drill press holder fitted with a stainless tamper and works a lot like the Macap Auto Tamp. It really shapes the puck beautifully and I can't but think that it played a huge role in creating tonight's honey-like pour.

Thanks so much Dan, everyone. I don't need that $250 home visit after all!

7 months after buy date I finally can drink a decent cup of espresso. I guess the lesson here is that every HX machine is different and has its own flush cycle.

Key
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#40: Post by HB »

I'm glad to see this come to a happy and cost-free conclusion. I would like to capture what you've learned to improve the Performance section of the buyer's guide. The excerpt below explains the routine I used:
To summarize the early-morning startup routine: Big Flush, pause three minutes, Double (flush), pause one minute, Mini Flush, pause one minute, Mini Flush, pause one minute, Mini Flush, pull your shot. Precisely following the suggested pause times to the second are not critically important and I integrated this into my normal preparation routine of gathering cups, cleaning out the grinder, measuring beans, and so on.
...

Keep in mind that the above suggestions are for those who really, really want to squeak the best shot from Junior straight out of the gate. If you're a "keep it simple" sort of person, the abbreviated routine after five or more minutes of idle time is just one step: Press Big Flush. There's no need to wait more than few seconds for the temperature to rebound before beginning the extraction. After the flush, lock in and press Double for a metered shot, or the Free Pour button to start the pump and a second time to stop.
Did you try this and it didn't work for you? Or does what you figured out work better?
Dan Kehn