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Date: 06 Sep 2006 12:36:56
From: Coffee for Connoisseurs
Subject: Rotary vs Vibe Pump Resolution
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Now we're getting over all the nasty things I said about the Aussie Synesso
owners (I wish, but I was prepared for the shitstorm), one of the <other >
myths I was busting last month deserves some recognition. I was finally able
to get two absolutely identical HX machines (except for the pumps), set them
up to the same boiler pressure, brew pressure and water debit, and observe
the differences in shot quality. There weren't any. End of story. Another
great source of endless theorizing laid to rest. See
http://www.coffeeco.com.au/newsletter/september2006.html .
--
Alan
alanfrew@coffeeco.com.au
www.coffeeco.com.au
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Date: 07 Sep 2006 11:12:10
From: Brent
Subject: Re: Rotary vs Vibe Pump Resolution
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> Now we're getting over all the nasty things I said about the Aussie
> Synesso owners (I wish, but I was prepared for the shitstorm), one of the
> <other>
interestingly I thought you were not so much bashing their selection of
machine, but the hype around it, but then I am prone to misinterpretation...
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Date: 06 Sep 2006 14:24:00
From: gscace
Subject: Re: Rotary vs Vibe Pump Resolution
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It may be tough to do tests with all variables neatly controlled, but
there is a growing body of evidence that points to the conclusions that
Alan has drawn. Jim and Ken's experiments drew that conclusion, and I
believe that those were pretty carefully done. I've thought that there
wasn't any substantive difference between pump types for a long time,
ever since doing the Silvia pressure control stuff. Coffee doesn't
posess any magical qualities that allow it to see what produces the hot
pressurized water. If the water is presented to the coffee in a
consistent way, regardless of the method, then the results will be the
same in the cup, and similarly independent of heating and
pressurization technique.
That's my belief anyway. This stuff ain't magic.
-Greg
Omniryx@gmail.com wrote:
> Dan Bollinger wrote:
> > Alan, Not so fast. While I have no opinion on rotary vane pump v. impulse pump
> > (my machine uses neither!), your test is not conclusive. 'End of story' may be
> > premature.
>
> Dan is absolutely right. The conduct of valid and reliable coffee
> taste tests to any acceptable scientific standard is nearly impossible.
> Are you prepared to say that the grinds were precisely the same? That
> the weight of coffee in each basket was precisely the same? That the
> tamp was precisely the same? That the temperature of the water, the
> PF, even the cup were precisely the same? That the shot times were
> precisely the same? Did you perform multiple observations with
> multiple evaluators?
>
> No, I didn't think so. So Dan's judgment stands. We don't "prove"
> things in this way. And even if we did, you didn't.
>
> Will
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Date: 06 Sep 2006 19:03:38
From: Ken Fox
Subject: Re: Rotary vs Vibe Pump Resolution
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"gscace" <gregory.scace@nist.gov > wrote in message
news:1157577840.391957.44030@h48g2000cwc.googlegroups.com...
> It may be tough to do tests with all variables neatly controlled, but
> there is a growing body of evidence that points to the conclusions that
> Alan has drawn. Jim and Ken's experiments drew that conclusion, and I
> believe that those were pretty carefully done. I've thought that there
> wasn't any substantive difference between pump types for a long time,
> ever since doing the Silvia pressure control stuff. Coffee doesn't
> posess any magical qualities that allow it to see what produces the hot
> pressurized water. If the water is presented to the coffee in a
> consistent way, regardless of the method, then the results will be the
> same in the cup, and similarly independent of heating and
> pressurization technique.
>
> That's my belief anyway. This stuff ain't magic.
>
> -Greg
I would even be willing to consider the possibility, no matter how remote,
that there IS a discernable difference between the output of the two types
of pumps, but that this difference is so small that you'd need a test at
least an order of magnitude larger than what Jim and I have done (our test
having the greatest number of tasters, e..g. "2," and the greatest numbers
of paired shots tested). If that is the case than what this says is that
the importance of pump type is dwarfed by other factors such as the coffee
used, barista skills, and intershot variability.
So, even if there IS a real difference (and I'm open minded enough to
consider it's possible existance), the difference isn't worth the attention
it has received since the advent of rotary pumps in espresso machines.
ken
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Date: 07 Sep 2006 02:09:21
From: Espressopithecus (Java Man)
Subject: Re: Rotary vs Vibe Pump Resolution
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In article <4m99j3F57g8fU1@individual.net >,
morceaudemerdeThisMerdeGoes@hotmail.com says...
> So, even if there IS a real difference (and I'm open minded enough to
> consider it's possible existance), the difference isn't worth the attention
> it has received since the advent of rotary pumps in espresso machines.
>
This is just another example showing that in the absence of rigorous
unbiased testing, keting trumps truth.
Rick
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Date: 06 Sep 2006 22:02:57
From: jim schulman
Subject: Re: Rotary vs Vibe Pump Resolution
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On Thu, 07 Sep 2006 02:09:21 GMT, Espressopithecus (Java Man)
<rickk@letterectomyTELUS.net > wrote:
>This is just another example showing that in the absence of rigorous
>unbiased testing, keting trumps truth.
Actually, I'v heard that many Italians think vibe pumps make better
espresso than rotaries.
The myth has nothing to do with keting hype -- commercial 2+
groupers or even heavy duty single groupers have to be rotary just to
handle the traffic, whereas home machiness mostly must have vibes in
order to sell at an acceptable price (Quickmill's pre-vibe rotary home
machines were sales flops). Using "keting hype" to sell rotaries in
the home is a bit like thinking keting hypoe could selll a lot of
refrigerated warehouses as kitchen appliances.
The myth originates here in ac, an integral part of the "commercial is
better than domestic" thesis, which is, on the whole, true; but which
has a number of exceptions.
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Date: 07 Sep 2006 05:03:33
From: Donn Cave
Subject: Re: Rotary vs Vibe Pump Resolution
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Quoth jim schulman <jim_schulman@ameritech.net >:
...
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Date: 07 Sep 2006 17:01:32
From: jim schulman
Subject: Re: Rotary vs Vibe Pump Resolution
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On 07 Sep 2006 05:03:33 GMT, "Donn Cave" <donn@drizzle.com > wrote:
>
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Date: 07 Sep 2006 11:10:19
From: Brent
Subject: Re: Rotary vs Vibe Pump Resolution
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also read the article, Alan says the shots were delivered to him blind.
If Alan said thats how he did it, then that is so from my perspective...
Brent
> It may be tough to do tests with all variables neatly controlled, but
> there is a growing body of evidence that points to the conclusions that
> Alan has drawn. Jim and Ken's experiments drew that conclusion, and I
> believe that those were pretty carefully done. I've thought that there
> wasn't any substantive difference between pump types for a long time,
> ever since doing the Silvia pressure control stuff. Coffee doesn't
> posess any magical qualities that allow it to see what produces the hot
> pressurized water. If the water is presented to the coffee in a
> consistent way, regardless of the method, then the results will be the
> same in the cup, and similarly independent of heating and
> pressurization technique.
>
> That's my belief anyway. This stuff ain't magic.
>
> -Greg
>
>
> Omniryx@gmail.com wrote:
>> Dan Bollinger wrote:
>> > Alan, Not so fast. While I have no opinion on rotary vane pump v.
>> > impulse pump
>> > (my machine uses neither!), your test is not conclusive. 'End of
>> > story' may be
>> > premature.
>>
>> Dan is absolutely right. The conduct of valid and reliable coffee
>> taste tests to any acceptable scientific standard is nearly impossible.
>> Are you prepared to say that the grinds were precisely the same? That
>> the weight of coffee in each basket was precisely the same? That the
>> tamp was precisely the same? That the temperature of the water, the
>> PF, even the cup were precisely the same? That the shot times were
>> precisely the same? Did you perform multiple observations with
>> multiple evaluators?
>>
>> No, I didn't think so. So Dan's judgment stands. We don't "prove"
>> things in this way. And even if we did, you didn't.
>>
>> Will
>
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Date: 06 Sep 2006 08:55:52
From: Ken Fox
Subject: Re: Rotary vs Vibe Pump Resolution
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"Coffee for Connoisseurs" <alanfrew@coffeeco.com.au > wrote in message
news:IhzLg.24332$rP1.922@news-server.bigpond.net.au...
> Now we're getting over all the nasty things I said about the Aussie
> Synesso owners (I wish, but I was prepared for the shitstorm), one of the
> <other> myths I was busting last month deserves some recognition. I was
> finally able to get two absolutely identical HX machines (except for the
> pumps), set them up to the same boiler pressure, brew pressure and water
> debit, and observe the differences in shot quality. There weren't any. End
> of story. Another great source of endless theorizing laid to rest. See
> http://www.coffeeco.com.au/newsletter/september2006.html .
>
>
> --
> Alan
>
> alanfrew@coffeeco.com.au
> www.coffeeco.com.au
>
This has been done two times before in a much more rigourous and controlled
fashion by Jim Schulman and myself using two very similar Cimbali Juniors.
All tasting was done blinded and a number of different coffees were used.
All obvious confounding variables were controlled.
http://groups.google.com/group/alt.coffee/browse_frm/thread/e84ce59fde4e7a57/c6bdb4cdd7f451fa?lnk=gst&q=tale+of+two+juniors&rnum=5#c6bdb4cdd7f451fa
http://groups.google.com/group/alt.coffee/browse_frm/thread/68421646961d4c19/ac898c065e2f6898#ac898c065e2f6898
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Date: 06 Sep 2006 09:58:12
From: Ken Fox
Subject: Re: Rotary vs Vibe Pump Resolution
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"Ken Fox" <morceaudemerdeThisMerdeGoes@hotmail.com > wrote in message
news:4m85viF50dn4U1@individual.net...
> "Coffee for Connoisseurs" <alanfrew@coffeeco.com.au> wrote in message
> news:IhzLg.24332$rP1.922@news-server.bigpond.net.au...
>> Now we're getting over all the nasty things I said about the Aussie
>> Synesso owners (I wish, but I was prepared for the shitstorm), one of the
>> <other> myths I was busting last month deserves some recognition. I was
>> finally able to get two absolutely identical HX machines (except for the
>> pumps), set them up to the same boiler pressure, brew pressure and water
>> debit, and observe the differences in shot quality. There weren't any.
>> End of story. Another great source of endless theorizing laid to rest.
>> See http://www.coffeeco.com.au/newsletter/september2006.html .
>>
>>
>> --
>> Alan
>>
>> alanfrew@coffeeco.com.au
>> www.coffeeco.com.au
>>
>
> This has been done two times before in a much more rigourous and
> controlled fashion by Jim Schulman and myself using two very similar
> Cimbali Juniors. All tasting was done blinded and a number of different
> coffees were used. All obvious confounding variables were controlled.
>
> http://groups.google.com/group/alt.coffee/browse_frm/thread/e84ce59fde4e7a57/c6bdb4cdd7f451fa?lnk=gst&q=tale+of+two+juniors&rnum=5#c6bdb4cdd7f451fa
>
> http://groups.google.com/group/alt.coffee/browse_frm/thread/68421646961d4c19/ac898c065e2f6898#ac898c065e2f6898
>
Actually, now that I remember it, the study has been done 3 times, the last
two times done with Jim Schulman. The first time (the thread from 2003,
above) had some uncontrolled variables which Jim Schulman pointed out before
we repeated it:
http://groups.google.com/group/alt.coffee/browse_frm/thread/8dac1a7ebe06b39c/80cd237817f4a604?lnk=gst&q=part+deux+ken+fox&rnum=1#80cd237817f4a604
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Date: 07 Sep 2006 11:13:25
From: Brent
Subject: Re: Rotary vs Vibe Pump Resolution
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What Alans test proves is that the same results are achieved when the
machines are upside down as well :)
Brent
>>> Now we're getting over all the nasty things I said about the Aussie
>>> Synesso owners (I wish, but I was prepared for the shitstorm), one of
>>> the <other> myths I was busting last month deserves some recognition. I
>>> was finally able to get two absolutely identical HX machines (except for
>>> the pumps), set them up to the same boiler pressure, brew pressure and
>>> water debit, and observe the differences in shot quality. There weren't
>>> any. End of story. Another great source of endless theorizing laid to
>>> rest. See http://www.coffeeco.com.au/newsletter/september2006.html .
>>>
>>>
>>> --
>>> Alan
>>>
>>> alanfrew@coffeeco.com.au
>>> www.coffeeco.com.au
>>>
>>
>> This has been done two times before in a much more rigourous and
>> controlled fashion by Jim Schulman and myself using two very similar
>> Cimbali Juniors. All tasting was done blinded and a number of different
>> coffees were used. All obvious confounding variables were controlled.
>>
>> http://groups.google.com/group/alt.coffee/browse_frm/thread/e84ce59fde4e7a57/c6bdb4cdd7f451fa?lnk=gst&q=tale+of+two+juniors&rnum=5#c6bdb4cdd7f451fa
>>
>> http://groups.google.com/group/alt.coffee/browse_frm/thread/68421646961d4c19/ac898c065e2f6898#ac898c065e2f6898
>>
>
> Actually, now that I remember it, the study has been done 3 times, the
> last two times done with Jim Schulman. The first time (the thread from
> 2003, above) had some uncontrolled variables which Jim Schulman pointed
> out before we repeated it:
>
> http://groups.google.com/group/alt.coffee/browse_frm/thread/8dac1a7ebe06b39c/80cd237817f4a604?lnk=gst&q=part+deux+ken+fox&rnum=1#80cd237817f4a604
>
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Date: 06 Sep 2006 18:21:06
From: I->Ian
Subject: Re: Rotary vs Vibe Pump Resolution
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>> This has been done two times before in a much more rigourous and
>> controlled fashion by Jim Schulman and myself using two very similar
>> Cimbali Juniors. All tasting was done blinded and a number of different
>> coffees were used. All obvious confounding variables were controlled.
>>
>> http://groups.google.com/group/alt.coffee/browse_frm/thread/e84ce59fde4e7a57/c6bdb4cdd7f451fa?lnk=gst&q=tale+of+two+juniors&rnum=5#c6bdb4cdd7f451fa
>>
>> http://groups.google.com/group/alt.coffee/browse_frm/thread/68421646961d4c19/ac898c065e2f6898#ac898c065e2f6898
>>
>
>Actually, now that I remember it, the study has been done 3 times, the last
>two times done with Jim Schulman. The first time (the thread from 2003,
>above) had some uncontrolled variables which Jim Schulman pointed out before
>we repeated it:
>
>http://groups.google.com/group/alt.coffee/browse_frm/thread/8dac1a7ebe06b39c/80cd237817f4a604?lnk=gst&q=part+deux+ken+fox&rnum=1#80cd237817f4a604
>
But, Ken, HOW, oh HOW, are we to give your results any credibility in
light of your recent post soliciting the donation of a GS3. I could
hear Jr's scream just as you hit Enter. [ TFIC ;-) ]
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Date: 06 Sep 2006 13:12:15
From: Ken Fox
Subject: Re: Rotary vs Vibe Pump Resolution
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"I- >Ian" <someone@nowhere.com> wrote in message
news:864uf297f1s332surnvtqsj4g7t7r9ktil@4ax.com...
>>
>
> But, Ken, HOW, oh HOW, are we to give your results any credibility in
> light of your recent post soliciting the donation of a GS3. I could
> hear Jr's scream just as you hit Enter. [ TFIC ;-) ]
Hi Ian,
I think the GS3 is a terrific machine and if I didn't already have two
perfectly serviceable machines I'd give it serious consideration. Plus, one
can do nothing but applaud the approach of LM towards their enthusiast
customers, something I can't say about Cimbali.
ken
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Date: 06 Sep 2006 06:29:08
From: Omniryx@gmail.com
Subject: Re: Rotary vs Vibe Pump Resolution
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Dan Bollinger wrote:
> Alan, Not so fast. While I have no opinion on rotary vane pump v. impulse pump
> (my machine uses neither!), your test is not conclusive. 'End of story' may be
> premature.
Dan is absolutely right. The conduct of valid and reliable coffee
taste tests to any acceptable scientific standard is nearly impossible.
Are you prepared to say that the grinds were precisely the same? That
the weight of coffee in each basket was precisely the same? That the
tamp was precisely the same? That the temperature of the water, the
PF, even the cup were precisely the same? That the shot times were
precisely the same? Did you perform multiple observations with
multiple evaluators?
No, I didn't think so. So Dan's judgment stands. We don't "prove"
things in this way. And even if we did, you didn't.
Will
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Date: 06 Sep 2006 09:19:30
From: Dan Bollinger
Subject: Re: Rotary vs Vibe Pump Resolution
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> one of the <other> myths I was busting last month deserves some recognition. I
> was finally able to get two absolutely identical HX machines (except for the
> pumps), set them up to the same boiler pressure, brew pressure and water
> debit, and observe the differences in shot quality. There weren't any. End of
> story. Another great source of endless theorizing laid to rest. See
> http://www.coffeeco.com.au/newsletter/september2006.html .
Alan, Not so fast. While I have no opinion on rotary vane pump v. impulse pump
(my machine uses neither!), your test is not conclusive. 'End of story' may be
premature.
First, some more information. Was this a blind test? That is, was the taster
unaware of which machine was used for each shot? How many shots were tested?
How were the shots evalutated/graded? How many testers were employed?
Lastly, one experiment is not conclusive, even if carefully run. It needs to be
duplicated by others before it can be called fact.
Dan
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Date: 06 Sep 2006 12:06:17
From: jim schulman
Subject: Re: Rotary vs Vibe Pump Resolution
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On Wed, 6 Sep 2006 09:19:30 -0400, "Dan Bollinger"
<danNObollinger@insightSPAMbb.com > wrote:
>Lastly, one experiment is not conclusive, even if carefully run. It needs to be
>duplicated by others before it can be called fact.
Those of us who do espresso testing and post the results have so much
respect for Alan that we duplicated his results in advance. Ken and I
have done a pair of tests on identical Cimbalis, Greg and Andy on
stock and rotaried Silvias. The results are in line with Alan's
Countless people have found that all the hypothesized deficits of vibe
pumps disappeared when they were controlled to the standard of roatry
pumps by using OPVs. This should be even more convincing for a truth
commisar, since its an honest to god, Popperian, falsification of a
standing hypothesis.
Finally, there are the beginnings of indications that controls beyond
the standard OPV bring benefits over both vibes and rotaries. I would
hypothesise that such improved controls will improve shot quality
regardless of pump type.
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