Cimbali Jr = sour everytime, why? - Page 2

Need help with equipment usage or want to share your latest discovery?
SamuraiE (original poster)

#11: Post by SamuraiE (original poster) »

Dan, I swear I must have read your review of this machine 15 times (along with all of the Cimbali King, K. Fox's stuff...nice on CG, nasty on Alt.com if you tempt him) and it was a big reason I went with Jr. in the first place. I understand your comments on the length of flush yet just want to point out that if my machine is idle for even the shortest amount of time the water will just explode out of the group with a sound that would wake the dead. The smallest flush you mention in your review does not even begin to slow down the jig the water is doing, nor the steamy sounds of water on fire (Can water be on fire? It was back when I was a kid in the 70's, we could drive up to Cleveland and watch Lake Erie ablaze).

Anyway, it usually takes at least 4oz to get anything that resembles a smooth flow of water out of the group. So, I guess what you are saying is to not flush 4oz and just go ahead and pull the shot with all that steam and splash and hope it keeps the group up to temp. Do you think boiler setting is going to make any difference?

As for the beans I am using, I ordered quite a load of greens from SM and use Mr. Monkey, Liquid Amber, SM Classic espresso blend and have even used lighter roasted beans one would not normally use for espresso (think most of the usual suspects from Africa and S. America) but rather a popular selection for use in a press pot or vacuum setup. Anyway, they always come out on the sour side....yet taste fine with any of the other machines I have in the house (basic paper filter, vacuum, etc).

Oh well, my cappas are always great. Jr. foams like a king. Guess I will try to flush less and.........um.....flush less?

OK, I am listening and no suggestion is too stupid so throw me a few more bones.
I am not worthy!

User avatar
HB
Admin

#12: Post by HB »

SamuraiE wrote:Do you think boiler setting is going to make any difference?
Junior is very thermally efficient, so the best boiler setting is lower than you might expect. I tried the range from 0.7 to 1.4 bar; 0.9 bar was the setting when the machine arrived and it worked best for me. FWIW, Ken lives at high altitude and his setting is even lower (I believe 0.7 bar).
Dan Kehn

Decent Espresso: espresso equipment for serious baristas
Sponsored by Decent Espresso
User avatar
malachi

#13: Post by malachi »

Lighter roasted coffees are more likely to contribute to your sour espresso as they tend to require higher brew temp. This can get even more noticable if your roast time is very short and your roast degree is light (ie. incorrect profile).

Suggest staying below 1BAR - this will help.
"Taste is the only morality." -- John Ruskin

SamuraiE (original poster)

#14: Post by SamuraiE (original poster) »

Malachi, yes, and that's why I almost always go with the espresso blends and roast according to SM guidelines. Thanks for your fine advice.

OK, Dan, gang...I am off to tame the beast! I will set the bar back to 0.9 and flush less. And when the nuclear flash (spraying water) hits, I will remember the words from my 2nd grade teacher: "Duck and cover!"

thanks all, Key
I am not worthy!

k7qz

#15: Post by k7qz »

I've been following this thread with some interest as I've been using a Junior user now for several weeks and he is clearly a different beast than the E61 "Pro" machine I used to have.

One thing that really stands out to me so far is the brewhead temperature stability of this unit. I don't know how many shots one would have to pull in an hour to overwhelm Junior but I don't think it would be an easy task!

I've also read Dan's Junior article several times and I agree it was very well done (like his others!). The recommended cooling routine suggested there was:

"If it's the very first time of the day (really, really idle), this flush raises the group to temperature, but a few extra flushes help get the big hunk of metal components called the brew group all singing to the same tune. To simulate the heating that naturally occurs over the course of the first half-dozen shots, follow Big Flush with Double three minutes later, and then three Mini Flushes at one minute intervals.

It's a few extra steps that really improves the first shot of the day. 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." ... snip

I wonder, given Junior's memory, if one might start with a Double flush rather than the Big Flush? I don't have a temp gauge to test this hypothesis.

Dan, any thoughts?

-Mike

User avatar
HB
Admin

#16: Post by HB »

k7qz wrote:I wonder, given Junior's memory, if one might start with a Double flush rather than the Big Flush? I don't have a temp gauge to test this hypothesis.
Unfortunately I don't have Junior any longer to test. It would have been nice to have a thermofilter to verify your hypothesis, but I'm certain Junior needs a big kick in the pants to get out of bed. The Big Flush serves this purpose. I documented similar behavior for the Elektra A3, but since it doesn't have volumetric dosing, I simply add three extra seconds of flushing first time out.
Dan Kehn

SamuraiE (original poster)

#17: Post by SamuraiE (original poster) »

Dan and anyone else who was kind enough to throw some advice my way.....thanks......I need a little more. If you recall Jr. gives me the sourpuss each and every time. Well on the last thread we covered flushing and warming up the group. I even went to the extreme of jacking the bar pressure as high as it would go to see if that would give me a bitter shot. It did, a little, I suppose.

Well after reducing the flush between pulls the shots taste better but usually get more sour the longer the session goes (first shot is always the best).

So here is my question: Is it possible that my machine just isn't getting the power it needs to fully reach proper brew temp? I'm thinking this is what is going on. The machine was built to match Japanese specs (100v) but the voltage in Japanese homes really spikes and drops sometimes well below 100v. Could it be that a line regulator (variac) would solve this problem? I talked it over with a fellow Jgeek and he suggested I ask everyone here at HB.

Would a lack of constant 100v of current cause the machine to not reach proper temp? As I mentioned above, just for the hey of it, I jacked up the bar pressure as high as it would go (1.6 bar) and without flushing before the shot managed to pull a really full-bodied, dark, tasty, very hot shot. Much darker than any pull at a lower setting. However, sure enough the next shot was not nearly as hot and had sour tones (no flush at all between the 2 pulls except for a pf wiggle immediately after the first shot).

Ideas?

Key
I am not worthy!

La Marzocco · Home: customized for espresso aficionados
Sponsored by La Marzocco · Home
User avatar
HB
Admin

#18: Post by HB »

SamuraiE wrote:So here is my question: Is it possible that my machine just isn't getting the power it needs to fully reach proper brew temp?
At times like this I wish you had a thermofilter so we could compare data with confidence. If your boiler pressure gauge indicates the proper pressure (e.g., 0.9 bar), then the lower voltage's only effect temperature-wise would be slower recovery. Reviewing this thread, I don't see any mention of the brew pressure. Have you checked that too (around 9 bar)?

I'm not convinced that there's a mechnical issue at fault, however a shortened HX injector would produce overall lower brew temperatures. A little background on this... When I first evaluated the prototype Andreja Premium, I noticed it pulled consistently cooler shots than other similar prosumer E61 machines at the same boiler setting. It also behaved much like you described - if I cranked the boiler setting way up to 1.6 bar, the first shot was close to the target temperature, but fell off rapidly in subsequent shots. I asked Quick Mill about it and they explained that the prototype was constructed using an injector length for the desired temperature range for the German market, whose brew temperature preferences run slightly lower than in the US. The Buyer's Guide was based off the production model destined for the US and behaved like the other prosumer E61s described in How I Stopped Worrying and Learned to Love HXs. It is possible that Cimbali similarly tunes their machine's natural temperature range for different markets; your local repair technician would know for certain.
Dan Kehn

SamuraiE (original poster)

#19: Post by SamuraiE (original poster) »

Dan, I have a group pressure gauge I bought from coffeeparts and I adjusted the group pressure from the preset 12 bar down to 9 bar. So I think we can be pretty sure that all the bar settings are correct.

As for your comments on injector length, I have to admit I don't know what you are talking about. Is this something I can adjust? If so, how do I reach it? Just looking at the diagram of my machine a few posts above I see 'Injector' but can't really find it in the pic.

Should I reset the group pressure back up to its original setting? Or maybe just start smacking the machine around a little, you know, get real tough with him....start dropping hints about Yakuza gang members on the way over to have a little chat with him, etc.

I am sure all this is just a simple adjustment away from getting the machine hotter and pouring out great shots....just I'll be damned if I can figure it out.

Don't know any techs around here....since I bought direct from Europe and not from the Japanese rep I doubt these islanders will be willing to come and have a look see at my machine....but I will call and endure their wrath just the same.

Key
I am not worthy!

User avatar
HB
Admin

#20: Post by HB »

SamuraiE wrote:As for your comments on injector length, I have to admit I don't know what you are talking about. Is this something I can adjust? If so, how do I reach it? Just looking at the diagram of my machine a few posts above I see 'Injector' but can't really find it in the pic.
It's the thin plastic tube that runs down the middle of the heat exchanger and isn't meant to be adjusted. Owen's Cimbuini surgery, Jan.24, 2004 has an excellent picture of it. BTW, though it has nothing to do with your problem, his commentary on the replacement of a damaged heat exchanger is hilarious and should be read from the beginning starting from "Jan 21" to fully appreciate.
I am sure all this is just a simple adjustment away from getting the machine hotter and pouring out great shots....just I'll be damned if I can figure it out.
I'm not so sure because the adhoc data you collected wasn't remarkably cool given the weaknesses of the measurement technique (low 90s) and potentially excessive flushing. My comment about the injector is grasping at straws. See if you can curry favor with a local repair technician and I'll ask one of the technicians at Chris' Coffee to read this thread and hopefully offer some new ideas.
Dan Kehn