Problem with channeling? Dose less and grind finer - Page 3

#21: Post by **malachi** » January 6th, 2009, 9:39 pm

Perhaps we should have an item in people's profile. "My idea of espresso is XXXXXXXX."

That way if someone is looking to replicate the shot they got at the Rome train station, they know who to ask for advice - just as someone could easily get advice for making espresso taste like brewed coffee, making espresso shot that taste like they were served in the PNW or trying to make shots that taste the way the coffee smells.

January 7th, 2009, 1:02 am

another_jim wrote: Both the Cimbali and Elektra are a lot bitchier on dose than the E61s, LMs or Synessos (don't know about the new NS or LS or DC). This explains why Ken and us Elektra owners are more skeptical about updosing.

Actually, this is not my experience with Cimbali Juniors (I have no experience with their multigroup machines, nor with any of their Bistro models).

For a number of years my standard dosing was to fill the basket with a mound on top, sweep off the excess, then tamp like hell and pull the shot. With my vibe machine, although I got occasional channeling, most shots were fine. I have weighed the basket contents a number of time with this approach, and the average weight was about 19g.

When I bought the "new" rotary (now 4+ years old) I put the vibe machine down in the basement, but continued dosing and basket preparation as before. I was getting more frequent channeled shots, but I really didn't pay this a lot of attention, being enthralled with owning a new machine and the fact that it didn't make a racket every time I pulled a shot.

<aside; am I the only person out there who has noticed that this whole espresso passion is a moving target, and as soon as we "deal" with one "problem," we end up creating others?>

Later, more than a year later, I decided to bring the vibe machine back up from the basement and in casual use of the two machines it dawned on me that it was "easier" to pull a good shot on the vibe than on the rotary, an obvious observation that hadn't registered with me before that time. Subsequently, Michael Teahan suggested in a phone call, when I complained about channeling on the rotary, that I put in a delay timer on the rotary pump plus a regulator on the input water line, giving me a regulated preinfusion water pressure preceding the all-out 9 bar assault from the rotary pump.

Later still, I played around with ~14g dosing and in short order discovered that I preferred the taste profile of the lesser-dosed shots, plus, there was virtually never a channeled shot with the lower dose range no matter how little basket preparation I did (mirroring the observations any home espresso enthusiast would have on a visit to Italy where the baristas do virtually nothing in basket preparation but seem to effortlessly produce decent shots).

My point in recounting this history is to say that the thing that changed in my own personal experience was the purchase of a rotary machine that lacked any semblance of preinfusion, as is easily confirmed by any owner of a modern D1 Cimbali Junior who uses a PF manometer to calibrate the machine; the pressure ramp up to 9 bar is immediate, whereas with a similar vibe machine the time it takes to get to 9 bar is about 6 or 7 seconds with a gradual ramp up.

As a result of this experience it is obvious to me that the Cimbali group and standard double basket has no problem with updosing (at least to 19g), rather it is the way that Cimbali has implemented the changeover to rotary pumps, e.g. no gradual pressure ramp up and no preinfusion. For anyone who wants to overcome this "limitation," the delay timer modification is a simple method that gets the rotary pump to behave more or less like a vibe pump, and this will eliminate frequent channeling assuming at least acceptable barista technique.

It is not the Cimbali machine design or group that is intolerant of updosing, rather it is the absence of any delay in the pressure ramp up, e.g. NO preinfusion.

Again, when all is said and done I no longer like the type of shot you get from updosed shots, but I'd have no problem making them on my Cimbalis, until the cows come home, if that is what I wanted to make in my house on my equipment.

It occurs to me now that Cimbali simply swapped in a rotary pump and motor (plus lots of electronics) in place of the vibe pump, without giving much thought to what this would do to the sort of puck that lots of people here in North America prepare. Their machine design process presumes the use of the sort of dose that you find in Italy, e.g. 12-14g for a double basket. If you eliminate the poor man's preinfusion that you get with a vibe pump by switching over to a rotary pump, and if your basket dose is ~14g, it doesn't matter; you still don't channel. But, if you updose, this is where the end product really suffers unless your basket preparation is nearly perfect, if the puck is to be assaulted with 9 bar from the first second.

ken

January 7th, 2009, 1:16 am

AndyS wrote:But seriously, my criticism of your "thread summary" is that it ignores the point that Chris, Jim, and others have made: there are other styles of espresso that cannot be prepared following your formula.

I don't disagree with you. I used to enjoy that sort of espresso and I used to make it much or most or almost all of the time. With the wisdom I have gained since then, I now realize the error of my ways and have changed my approach. That is all

ken

#24: Post by **cannonfodder** » January 7th, 2009, 9:26 am

There really is no one solution or style, if there were it would get boring very quickly. What keeps it interesting for me is the constant change. Every year a new crop brings new tastes and challenges, same with hardware be it machine or grinder.

The problem we run into is making the assumption that everyone is of a certain skill level and make specific recommendations based on that. Often those assumptions are off base. The grind finer, dose less mantra to fix your channeling problem assumes that the end user has the right temperature, good grinder, proper distribution, proper brew pressure, proper tamp, quality coffee, etc... The issue could be caused by any number of variables. I am guilty of making that assumption at times and blindly make a suggestion based on my experience when the person with the question does not have my experience be that good or bad.

While lower the dose answer often works for me, that is with my kit and my style of espresso. I have one of the afore mentioned Elektra's that absolutely hates to be dosed up. At the same time I have used E61 boxes and Marzocco's that did not really care how much coffee you jammed into the basket. I have also had channeling issues that were the result of the grinder and no matter how much you updosed, downdosed, it would not go away. The fix was getting a better grinder.

The style of espresso you enjoy is a very personal preference. Drink what you like and what your machine works best to produce. I do think that it would be a wise choice to try a coffee in many different forms. Some blends simply work best at a particular brew ratio. I enjoy experimenting with the extraction space. Sometimes I get a pleasant surprise, other times I get a rather unpleasant experience, but it does not keep me from constantly trying just to see what is around that next corner.

#25: Post by **another_jim** » January 7th, 2009, 8:33 pm

About the Cimbali being bitchy at high doses

Ken Fox wrote:Actually, this is not my experience with Cimbali Juniors (I have no experience with their multigroup machines, nor with any of their Bistro models).

It may be time for your Altzheimer's checkup, or at least to stop watching Fox News's talking heads. There's a boatload of posts about your preinfusion manipulations, your sink shots, etc. etc prior to your seeing the 14 gram light. So after all those posts lauding how much easier 14 gram shots are, you're now saying updoses on the Cimbali are easy?

January 7th, 2009, 8:49 pm

another_jim wrote:About the Cimbali being bitchy at high doses

It may be time for your Altzheimer's checkup, or at least to stop watching Fox News's talking heads. There's a boatload of posts about your preinfusion manipulations, your sink shots, etc. etc prior to your seeing the 14 gram light. So after all those posts lauding how much easier 14 gram shots are, you're now saying updoses on the Cimbali are easy?

Please reference these quotes, especially those that refer to my old vibe machine, since my alzheimers (as you call it) prevents me from remembering it. I don't recall having that experience with the vibe machine, but since you recall that I had it could you please refresh my memory on that?

ken

P.S. I don't come here seeking this sort of discussion