HomeRoast Digest


Topic: New list member intro and challenge (18 msgs / 391 lines)
1) From: David Yeager
Welcome Doug,
Nice  bio.  Seriously.  If you had had your metrics established 
beforehand, you would know that the half-life of an intro here is 
about seven or eight responses before the thread is hijacked OT in 
some unpredictable direction!  You are a standard deviation or two 
beyond that, ergo, must have been the bio!
I will be looking forward to reading some of your esoteric excursions 
into metrics, although I may only adapt a few for personal use.  ;^)
Here is an extraction question for you:
Given that low brewing temperature can lead to a sour taste and too 
high brewing temps can lead to a bitter taste (and some similar 
function for grind size); is it true that, as a function of time, - 
the first extractions in brewing are sour; mid-stream are "balanced"; 
last parts out are bitter?  If so, how come?
I have read that champion baristas only catch the "mid-stream" 
portion of their pulls, letting the first and last parts go by.  Is 
this sour-sweet continuum the reason why?
David Y
Techie Lite
Atlanta

2) From: Les
David,
If your temp is right from the start and you have a proper tamp you don't=
 
have to go to such extremes for excellent espresso. I consume my whole shot=
!
 Les
 On 8/24/05, David Yeager  wrote: 
<Snip>

3) From: David Yeager
At 01:08 AM 8/25/2005, you wrote:
<Snip>
But, Les, you also pray over your shots, which is tantamount to cheating.
This here is an empirical queschun.  ;^)
David Y

4) From: Pecan Jim Gundlach
Les,
     I have to disagree, I find it is not just a temperature issue,    
No matter how good the grinder, it will produce certain "fines" that  
come through with the very first part of the shot.  On the  
temperature side, the coffee will always cool the first water  
through.  I find discarding the pre-creama part of the shot, usually  
about 3/4's a second's worth improves the shot.
         Jim Gundlach
On Aug 25, 2005, at 12:08 AM, Les wrote:
<Snip>

5) From: Douglas Strait
David Yeager wrote:
<Snip>
Taste is of course subjective so I cannot address the "truth" of the 
specific perceptions of sour/balanced/bitter. From my own experience 
with drip, it is most certainly true that the flavor is different 
during different portions of the extraction stream. The "how come" is 
likely due to the differing "solubilities" of the various components 
of the coffee that get moved from the grounds to the resulting brew. I 
place "solubilities" in quotation marks since I believe that solution 
is not the only mechanism involved. Others that come to mind are 
suspensions and emulsions. The early part of the extraction stream 
will be more biased towards the more "soluble" components and the 
later part more biased towards the less soluble components.
Doug, who is drinking a sufficiently balanced cup of Panama Eleta as 
this is being typed.

6) From: David Yeager
At 07:18 AM 8/25/2005, you wrote:
<Snip>
Jim,
         Then the first part would be bitter, rather than sour.  Right?
David Y

7) From: Pecan Jim Gundlach
On Aug 25, 2005, at 7:22 AM, David Yeager wrote:
<Snip>
David,
     That is how I would describe it.
          jim

8) From: John Blumel
On Aug 25, 2005, at 8:22 am, David Yeager wrote:
<Snip>
No. See,
   http://www.home-barista.com/espresso-guide-skills.htmland the Shot Time/Shot Volume graph (and accompanying text) in the  
"Working the Shot" section.
John Blumel

9) From: Alchemist John
On the temperature side, getting on a geek technical discussion, 
theoretically, would it be possible that a subtle reverse temperature 
ramp might alleviate or minimize this.  Hit the puck with slightly 
higher temperature water initially so that the resulting extraction 
temperature is appropriate, then reduce the temperature so as not to 
have too high of an extraction temperature for the rest of the 
shot.  I realize this would be an "interesting" engineering feat, but 
I just wonder if it might have some merit.
At 04:18 8/25/2005, you wrote:
<Snip>
John Nanci
AlChemist at large
Zen Roasting , Blending & Espresso pulling by Gestalthttp://www.chocolatealchemy.com/

10) From: David Yeager
At 08:44 AM 8/25/2005, John Blumel wrote:
 >On Aug 25, 2005, at 8:22 am, David Yeager wrote:
 >
 >> Then the first part would be bitter, rather than sour.  Right?
 >
 >No. See,
 >
 >   http://www.home-barista.com/espresso-guide-skills.html >
 >and the Shot Time/Shot Volume graph (and accompanying text) in the
 >"Working the Shot" section.
Thanks for the link, John.
 >>Then the first part would be bitter, rather than sour.  Right?
 >David,
 >     That is how I would describe it.
 >          jim
Thanks PecanJim.
No, Yes, No, Yes.
Oh, Boy.  Food fight!!   :^)
David Y
Atlanta

11) From: Robert Avery
Hi Doug, I myself would think that is not true, at least to any degree of 
extreme heat transfer. If you let the PF heat to the Group temp ... the 
coffee itself doesn't have enough mass or heat convection capability to 
absorb the kind of heat you are talking about to amount to anything. Now ... 
If you throw a cold PF  in ... that could gum up the works ... my opinion 
just based on my current understanding ... as for me I don't want to throw 
any of the pull away ... greedy I guess. Later, Bob
<Snip>

12) From: David Yeager
 >At 08:44 AM 8/25/2005, John Blumel wrote:
 > >On Aug 25, 2005, at 8:22 am, David Yeager wrote:
 > >
 > >> Then the first part would be bitter, rather than sour.  Right?
 > >
 > >No. See,
 > >
 > >   http://www.home-barista.com/espresso-guide-skills.html > >
 > >and the Shot Time/Shot Volume graph (and accompanying text) in the
 > >"Working the Shot" section.
 >
 >Thanks for the link, John.
 >
 > >>Then the first part would be bitter, rather than sour.  Right?
 >
 >
 > >David,
 > >     That is how I would describe it.
 > >          jim
 >
 >Thanks PecanJim.
 >
 >
 >No, Yes, No, Yes.
 >Oh, Boy.  Food fight!!   :^)
 >
 >David Y
 >Atlanta
OK, a the risk of avoiding a food fight, let me see if I understand 
and can reconcile what the two of you are saying.
John, the chart you cite gives the general parameters of espresso 
extraction, by shot volume, grind size and time.
Jim, you are pointing out that said chart does not take into account 
the compounding effect of those wascally "very" fines, which give an 
immediate (and unrepresentative) over-extraction.  And, this effect 
is not shown in the cart because it is too generalized (coarse, 
medium, fine) to include this effect.
Did I get it right?
David Y
Techie Lite
Atlanta

13) From: Les
Jim,
I don't mind a bit of grounds in my shots, but it doesn't happen very often=
. 
I found by dumping the first part of the shot, it loses a lot of the 
complexity. I also think my E-61 grouphead and being able to do an 8 sec.=
 
preinfusion helps a lot! I normally do an 8 sec preinfusion with a 22 secon=
d 
shot.
 Les
 On 8/25/05, Pecan Jim Gundlach  wrote: 
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e 
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s 
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ot!
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14) From:
<Snip>
portion of their pulls, letting the first and last parts go by.  Is
this sour-sweet continuum the reason why?<<<
David:
There are sure damn few champion baristas around then...
I have never seen a barista even pay much attention to what flows from the PF.
ginny

15) From:
Just imbibing some C+ Ethiopian Sidamo/ 3% Indian MMG. Just playing with th=
e 
new-burred Mazzer Major set to 38/100 on the dial. No kidding, and as I was=
 
first finding the Zero point and checking the grinds with a 10X loupe, Look=
, 
Ma, NO FINES ! ! !
That's huge to me. At the zero point, it ground a consistent gritty powder,=
 
with NO FINES ! ! ! And this E. Sidamo shows it.
The fines extract far more rapidly than your nominal grind, and they 
overextract in a flash, too.
Any brewing process that takes place over an extended period of time is a=
 
compromise. The initial stream will necessarily be under extracted, except=
 
for the Fines- they'll be Fine! [That's a Halo Halo cup in the Philippines!=
]
Early to mid-stream, the nominal grind will be extracting more properly and=
 
the Fines will start to overextract- Halo Halo!
As the brew progresses, extraction keeps shifting towards over extraction. =
I 
don't think anybody willingly chooses to fill his cup from the tail end of=
 
the drip stream, do you?
"...how come?" it's just one of those things. 
I'm a judge. Give me your beans! -RayO, aka Opa!
On 8/25/05, Douglas Strait  wrote:
<Snip>
-- 
"When the theme hits the bass, I dance the Jig!" - -Virgil Fox at the 
Wichita WurliTzer

16) From: Pecan Jim Gundlach
Les,
     As soon as I got home I went ahead and pulled a shot without  
discarding the first part and I simply do not like it as much as the  
one I had this morning.  The roast is Harar Horse, roasted just a tad  
too far about 44 hours ago.  It should really need the rest so for  
that reason alone, it should be better now, about twelve hours  
later.  Bitter may not be the word for what I'm tasting that I don't  
like but I'm at a loss for other words to describe it.  I did not pre- 
infuse because I wanted to limit the number of variables I changed.   
In addition to something of an unpleasant taste added, there is a  
lack of the smooth feel to the tongue.
       Jim
On Aug 25, 2005, at 9:38 AM, Les wrote:
<Snip>
"The espresso machine is an accessory to the grinder, not the other  
way around."

17) From: Les
We have different machines and maybe different tastes. I really like my 
shots and I know you really like yours. That is what is important! With my=
 
microprocessor control panel, I can get good repeatability on my times.
 Les
 On 8/25/05, Pecan Jim Gundlach  wrote: 
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I 
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the 
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18) From: Francis Cashman
I've seen the Australian World Barista Champion of two years ago using a 
relatively cheap machine and he uses all the pull to prodce very nice 
coffees.
FC


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