HomeRoast Digest


Topic: Judging the roast (65 msgs / 1672 lines)
1) From: John Abbott
Mark,
Which book did you buy? I think it might be worth the price just to get the
color chips.
John - Jury duty is NOT fun down here! 
--

2) From: John Abbott
Sorry - I'm using a HotTop.  It is programmable from 1 to 7.    One would=
 be
a light roast with 7 being something approaching charcoal.   I can extend
any roast by 1.5 minutes with the Plus key at the end of the roast if nee=
d
be.
John
--

3) From: Mark A. Chalkley
I just roasted up a batch (3 half-cups) of Yirgacheffe.  I've been
harboring a suspicion lately that my roasts have been a bit darker
than I thought they were.  (I know that sounds a bit dumb - but you
know what I mean...)  Then, I bought Davids' home roasting book and,
based on the color chips in the back, my suspicions have become almost
confirmed. So, this batch is lighter than the previous, but probably
closer to what is truly a FC, C+, C "bracketed" roast.
All of which is to say that I wonder how everybody else judges degree
of roast.  You certainly can't rely on the online color samples shown,
because every monitor is different, even if the web page itself is
perfect.  Are there any other ways?
On a related note, is there a cheaper way to get the full set of color
chips that the SCAA offers or, better yet, something similar?  $295
seems a bit excessive to me.  After all, if you knew what you were
doing, you could pick the correct colors out of a few paint
manufacturers' chip cards and have the reference for free. ;>)
Mark C.
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4) From: Mark A. Chalkley
John,
You're welcome!  I'm pretty sure the chips are accurate, but I sure
wish the chips had been chosen with the home roaster in mind, instead
of just trying to represent the whole spectrum.  That's not nearly as
useful.
I think that if Agtron or SCAA could offer an abbreviated set of chips
for the home roaster at a reasonable price, they'd make a lot more
money in the long run, assuming that's the general idea...
Mark C.
On Monday, September 16, 2002, 5:28:59 PM, you wrote:
JA> Mark,
JA> Gracias Amego!  I'll get it ordered in a couple of seconds here.  We really
JA> need a standard that is affordable. I gave some long consideration to the
JA> SCAA chip set, but that's a lot of money for an amateur group.  Besides all
JA> that, Kenneth Davids is probably the most quoted author on our list.
JA> Thanks
JA> John
JA> --

5) From: Lee XOC
< [mailto:homeroast-admin]On Behalf Of Mark A.
< Chalkley
< Sent: Monday, September 16, 2002 2:11 PM
<
<
< All of which is to say that I wonder how everybody else
< judges degree
< of roast.  You certainly can't rely on the online color
< samples shown,
< because every monitor is different, even if the web page itself is
< perfect.  Are there any other ways?
I'm not the most knowledgeable bean in the batch, but I don't know of
any way to judge the degree of roast after the fact.  I only know how
roasted my beans are by being present during roasting and timing the
roast relative to the crack stages.
I suppose it's possible to make educated guesses about degree of roast
from the flavor, but you'd have to know the beans I'd think.  Same
would also go for color.  Some beans are notorious for darkening early
on, others for remaining light or mottled well into 2nd crack.
- - - - - - - - - - - - - - -
Lee
San Diego,
California
------------------------------
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6) From: dewardh
Mark:
<Snip>
of roast.  You certainly can't rely on the online color samples shown,
because every monitor is different
You can't rely on color when roasting anyway, because each variety of bean is 
different as well.  There is no "one color fits all".  Not to say that color 
isn't a good guideline, once you're used to a particular variety, but . . .
I've come to think that temperature is really the only reliable indicator of 
degree of roast.  The best way to determine temperature is, obviously, to 
measure it, but as previous discussion here shows that's often easier said than 
done.  Fortunately for us the beans measure it also, and "report out" at two 
points . . . first and second crack . . . and those points are, as is the 
chemistry associated with them, consistent across variety to a far greater 
degree than is surface color.  That the color of ground beans tracks 
temperature at least reasonably well is, of course, the basis of the whole 
agtron system, but it's less useful than one might desire in the last moments 
of a roast when one really wants to know . . . .  And a thermometer is a 
*lot* cheaper than a set of chips . . .
FWIW, I drank Peet's for years before getting into home roasting, and thus used 
to think that dark and oily was what "good" coffee was.  Now it's a rare roast 
that I'll let show more than a few spots of oil in the roaster . . . *never* so 
much that it's not all reabsorbed by the time the beans are cool.  When I see 
oil on a bean now I automatically think either "over roasted" or "too old". 
 And, for the record, my wife and I drink only espresso.
Deward
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7) From: Mark A. Chalkley
On Monday, September 16, 2002, 6:10:54 PM, you wrote:
LX> I'm not the most knowledgeable bean in the batch, but I don't know of
LX> any way to judge the degree of roast after the fact.  I only know how
LX> roasted my beans are by being present during roasting and timing the
LX> roast relative to the crack stages.
LX> I suppose it's possible to make educated guesses about degree of roast
LX> from the flavor, but you'd have to know the beans I'd think.  Same
LX> would also go for color.  Some beans are notorious for darkening early
LX> on, others for remaining light or mottled well into 2nd crack.
I think the color system is designed to be used on the ground coffee,
not the roasted beans, so that would even the color considerably.  Of
course, different beans will taste different at the same degree of
roast, but I guess the theory is that you've got to have a standard of
some sort, and that's about as close as you can get to one.
Mark C.
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8) From: Mark A. Chalkley
John,
On Monday, September 16, 2002, 6:27:01 PM, you wrote:
JA> I'm with you there Dan.  My problem was interpreting light city to Full City
JA> to aggressive full city.  That's pretty fine tuning since what I produced
JA> was more like Vienna. :O(     I don't log by color - I log by time from the
JA> cracks. I know that a setting of 4 will produce a light roast - 6 about as
JA> dark as I EVER want to go - and who knows what 7 brings - I ran out of nerve
When you refer to the numbers 4-7 above, which roaster are you using?
Mark C.
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9) From: Mark A. Chalkley
Dan,
On Monday, September 16, 2002, 6:31:45 PM, you wrote:
DB> Ah, I missed that.  I'm still looking into borrowing an Agtron set
DB> and matching them to my Sherwin-Williams color chips.  That way we
DB> all could have the same set of colors and for free!  :)
You're talking my budgetary language now!  ;>)  Keep me posted if you
find out anything...
Mark C.
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10) From: Mike McGinness
From: "Mark A. Chalkley" 
On a related note, is there a cheaper way to get the full set of color
<Snip>
A few months back this was discussed. Same idea to have someone match them
to paint samples. I believe someone said a complete replacement set of just
the tiles was available from the SCAA. I didn't follow up on it then. The
replacement tiles aren't listed with the other 'stuff' for sale on their
site so I just shot them an email inquiring about price and how to order...
And yes you are correct that they are designed to compare ground, not whole
beans.
MM;-)
Home Ju-Ju Variable Variac Rockin' Rosto Roasting in Vancouver, WA USA
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11) From: Jack Berry
I was thinking of this a few weeks ago and wrote SCAA asking about the
availability of individual tiles. I only roast to a narrow range of color,
so why buy all the chips. In fact I thought at the time that #'s 45, 55 & 65
would probably be all I ever wanted. They reply from Kimberly Welty at SCAA
follows:
Hi!
They are $20 per tile.  I would need to know which tiles and your shipping
and credit card details.
Regards,
Kimberly Welty
SCRC/Special Projects Coordinator
Specialty Coffee Resource Center
Specialty Coffee Association of America
One World Trade Center, Suite 1200
Long Beach, CA 90831
Tel:  562-432-7222
Fax: 562-624-4103
E-mail:  kwelty

12) From: James Gundlach
On Monday, September 16, 2002, at 09:25 PM, Jack Berry wrote:
<Snip>
Sherwin-Williams sounds better by the minute.  That is about five pounds 
of green.
Jim Gundlach
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13) From: Mark A. Chalkley
Dan,
On Monday, September 16, 2002, 11:09:35 PM, you wrote:
DB> I don't see how, unless they are very short sighted.  Its' not
DB> like any of us are going to go out and buy and $11,000 Agtron
DB> colorimeter, or join the SCAA as a corporate member.
I certainly hope you're right.  It's a logical argument.  Maybe that's
what bothers me... ;>)
DB> That's the nice thing about this plan, the S-W chips are free and
DB> available at a store near you.  Only thing you need is the S-W
DB> chip number, and therein lies the problem.  Dan
Are even the larger chips available to "regular joe's"?  There's
another thing, too:  Wonder what a run on brown chips would do to the
S-W color scheme prophets/statisticians?  We could be influencing
Interior Decorating designs for decades to come here.
Mark C.
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14) From: Andrew Thomas
--- "Mark A. Chalkley"  wrote: (Re: Sherwin-Williams paint chips)
<Snip>
Cool! I may pick some up just to contribute to the future of home decorating. Seriously (ahem), it would probably only work if we all bought the actual paint.
Andy
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15) From: Dan Bollinger
<Snip>
Individual ones might be.  I've lost one or two large sheets and they mail
replacements for free. If this plan works, I'll post the address and chips
so everyone can write off for the larger ones.
<Snip>
Annual Design colors are from a Chicago group that researches trends.  The
reason I've chosen Sherwinn-Williams is because they don't change their
colors from season to season.  Instead, they keep a larger, more complete
set availale year after year. That's why most Interior Designers specify
S-W.  Interior Decorators?  Well, the less said about them the better.  ;)
Dan
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16) From: Irene and Lubos Palounek
"OK Gary, what I hear is that even if we all got some kind of reference
chip, it would only narrow things because of the difference in lighting -
and interpretation."
John and Gary, the lighting situation is easy to solve -- everybody should
use the OttLite -- see the www.ott;ite.com site The L13331 (UPC Code
7-61712-10115-6) is available from Costco and some other places for under
thirty dollars.  I have noticed that the beans and color pictures that look
the same under our regular kitchen light, look different under the desk
light, different again under the northern window light.  The OttLite
illumination is the closest one to the "Northern Light".
In my opinion, Sweet Maria's should sell the OttLite.  Consistent, correct
light source is a must for judging colors.
Cheers, Lubos
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17) From: jim gundlach
On Tuesday, September 17, 2002, at 07:24 AM, Irene and Lubos Palounek 
wrote:
<Snip>
Since I'm on the cheap side, I think I'll use sun light.  Ah, I'll even 
be generous, I'll let you all have some for free.
Jim Gundlach
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18) From: C. Marley
jim gundlach wrote:
<Snip>
LOL!   Every coffee I have ever roasted looks different at the same
stage of crack, at the same roast time, and whether it is roasted
quickly in the air roaster or slowly in the wok.  THEN difference in
lighting comes in! The only way to "judge a roast", IMHO, is with your
nose and tastebuds! 
Regards, Cathy
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19) From: C. Marley
"Mark A. Chalkley" wrote:
<Snip>
That is like defining "rare", "medium rare", and "medium" steak.  It is
a range rather than a definition.  In order to define you need specific
characteristics that are consistent.  Color varies with the type of
bean, so is not reliable.
  
One of these consistent characteristics I have found is that what I call
city roast is after first crack and a bit of browning, the bean has no
specific color, but the surface is dull and shows a slightly visible
surface veining or marbling.  
At full city, the beans have a uniform "satiny" finish to the surface,
but no oiliness at all.  
In an "aggressive full city" there is a slight oil sheen on the surface
- a slight oiliness that disappears as the beans cool.  
At what I call "Vienna" the beans retain the sheen even when cool, and a
few have some persistent oiliness, usually only at one end of the bean
or only on the flat side of the bean.
At "French" the beans are dark and oily, but not black.
The problem is that we have not adopted a consistent definition of this
sort.  Perhaps it would be useful for someone on this list, or Tom
himself, to define the roast depth in terms of the physical
characteristics of the beans such as my own personal scale has attempted
to do.
-- 
Regards, Cathy
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20) From: Bart Frazee
On Tue, 17 Sep 2002 07:24:43 -0500, you wrote:
<Snip>
-
<Snip>
should
<Snip>
under
<Snip>
look
<Snip>
correct
<Snip>
On the other hand we can use the sun. We all have it available, it
doesn't change frequency of light output with age, and it is FREE.
<Snip>
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21) From: Mike McGinness
From: "Bart Frazee" 
 doesn't change frequency of light output with age
Are you sure? Can you prove it!:-)
MM;-)
Home Ju-Ju Variable Variac Rockin' Rosto Roasting in Vancouver, WA USA
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22) From: Irene and Lubos Palounek
"On the other hand we can use the sun. We all have it available, it doesn't
change frequency of light output with age, and it is FREE."
Bart,
have you ever tried to take the "same" color picture at the sunrise, ten
o'clock in the morning, noon, five o'clock in the afternoon, just before
sunset? Add a picture illuminated by the Northern Sky. The color of the sun
light changes dramatically.
That's why I use the Ott-Lite when color is important.  Much more for color
photo printing and for the "digital darkroom" as compared for coffee
roasting. I believe that it is a very useful light source for anybody using
colors.
I fully agree with Cathy; other things, like sound and smell, are much more
important.  That's why I hesitate to order and use any "color references"
for coffee -- I am not sure WHY I would actually use them.
Anyhow, the color of the coffee should be compared after grinding, correct?
Not easy when trying to decide when to stop the roasting process.
Cheers, Lubos
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23) From: Bart Frazee
On Tue, 17 Sep 2002 09:04:59 -0700, you wrote:
<Snip>
 :)  At least not to the extent man made lamps do.  :)
<Snip>
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24) From: jim gundlach
On Tuesday, September 17, 2002, at 11:24 AM, Irene and Lubos Palounek 
wrote:
<Snip>
This is just something else to learn.  I already have a sense of how the 
color changes when I grind the coffee.
Jim Gundlach
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25) From: Angelo
Sometimes, especially in the summer, I like to roast at night, when it's a 
bit cooler. And, try as i may(might?), I can't get the sun to hang around 
past its bedtime. 
BTW, I've read Ott's books, years ago...very interesting...
Ciao,
Angelo
<Snip>
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26) From: Angelo
But, on the other other hand, clouds don't get in the way of the 
Ottlite....
A..
<Snip>
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27) From: Angelo
Dr. John, creator of Malabar Gold, in his directions for roasting that 
particular blend, suggests that one should roast just until a hint of sheen 
is seen on the bean , and to make 
note of that point. Then in subsequent roasts, to stop before that point.
I imagine the same thing can be done by the  pulling of some beans from 
successful roasts and  comparing these to the swatches..It would 
take  about ten seconds to pull and crush some beans. This could be done on 
one of the heater "stalls' for those who do that sort of thing...
Ciao,
A
<Snip>
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28) From: Andrew Thomas
--- "C. Marley"  wrote:
<Snip>
Cathy,
I'm with you. I think your descriptions are as good as any I have read, and more useful (to me at least) than color tiles or facsimiles thereof. It may be possible and interesting to match roasted coffee to color chips, but I don't see how it will help us to roast better.
Andy
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29) From: Kevin DuPre
I've seen a number of posts regarding this thread and
there is something that is being overlooked.
You would be comparing the coffee AND the color tile
under the same lighting conditions. This would make
the type of lighting (unless VERY DIM) irrelevant.
You'd be comparing apples for apples in the same
lighting conditions.
The reply about photographs under sunlight at various
times of day is also irrelevant.  I can state this
from nearly 35 years as a photographer, although an
amateur one.
The angle of sun through the atmosphere early and late
in the day is very shallow and has to go through more
of the atmosphere before illuminating the scene that
you are about to photograph.  While our eyes can
compensate for it, color film cannot and the industry
refers to this as "red shift". Consequently a clear
blue sky vs an overcast one will tend to "blue shift"
the film, but most color DAYLIGHT films are already
compensated for this. Hypothesizing about how sunlight
throughout the day will bias a color comparision using
your eyes is just not relevant, unless it is early
dawn or late dusk.
Again, as I stated, since you will be comparing an
actual Agtron color reference to the ground coffee
(per SCAA recommendations as to its use), with your
eyes, the lighting conditions are irrelevant - that's
the purpose of using a reference.
Regards,
Kevin
=====
--
Kevin DuPre
obxwindsurfhttp://profiles.yahoo.com/obxwindsurf"The real voyage of discovery consists not in seeking new landscapes but in having new eyes -- Marcel Proust"
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30) From: James Gundlach
On Tuesday, September 17, 2002, at 04:40 PM, Kevin DuPre wrote:
<Snip>
Wish I had thought of that.
Jim Gundlach
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31) From: John Abbott
Lubos,
Now that is within most budgets. I have been wanting one since you
talked of looking into your roaster with one.  I worked below ground
level at the Skunk Works in Seattle and we had Ott-lights in the
overhead. Uncle decided that we would feel less "submerged" with sun
like light. I always chuckled a bit about that - we were working with
lasers and wore goggles about 70% of the time :O)
On Tue, 2002-09-17 at 07:24, Irene and Lubos Palounek wrote:
<Snip>
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32) From: Dan Bollinger
<Snip>
Well, not exactly, but for our uses probably close enough. There is a
optical effect called metamerism where colors shift in chroma (color) and to
a lesser extent value (lightness/darkness) depending on the color of the
light source. A color mismatch can ocurr when two exactly matching colors
are made using disimilar pigments.  For instance, ground coffee and a color
tile may match under sunlight, but mismatch in chroma or value under
incandescent or flourescent. You have probably seen the variable light
sources in paint departments. This is intended to reduce metamerism. Of
course, the Agtron color chips are intended to be used comparatively, like
you say.  Dan
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33) From: John Abbott
Bart,
Sorry but you're wrong here when you say that we all have the sun.  You
have forgotten that we have several list members living in the Great
Northwet (s omitted on purpose).
As long as we are beating this dead horse - now we not only will have
long posts as to what color, what temperature, where the cracks occurred
but -- what time of day, sun angle , cloud proximity - background colors
- and what we had for lunch :O)
I'm going to keep looking for a standard - there MUST be something out
there.
:O)  JOhn
On Tue, 2002-09-17 at 11:00, Bart Frazee wrote:
<Snip>
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34) From: Tom & Maria
<Snip>
  It's a little out of our range -though it is a useful home roaster 
tool... also, you NEVER want to compete with costco since their 
prices are usually lower than wholesale sources.
BTW: I don't really think the SCAA roast tile kit is that useful. I 
think there's no substitute for learning the look, smell and sounds 
of the roast for different coffees, and a universal color kit is not 
going to account for the variations in roast color.  Sumatra is much 
lighter at City roast than Brazil dry process , etc, etc. You can 
have balanced light and ink sets, and still not nail down a roast for 
a coffee. Also, you are going to have more surface roast development 
in an air roast (and more bean expansion, as well as a smoother bean 
texture) than a drum roast. Judging the whole bean with tiles is very 
tricky due to the surface texture, but the grind of roasted coffee 
will also affect the perception of color. Anyway... I am just playing 
Devil's Advocate here, because after trying to incorporate the tiles 
into my regular roast documentation regimen on the Diedrich a few 
years back, I just found them to be less reliable than my other 
senses...
Tom
<Snip>
--
                   "Great coffee comes from tiny roasters"
            Sweet Maria's Home Coffee Roasting  -  Tom & Maria
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35) From: R.N.Kyle
Cathy, 
That seems to sum it up. I think your idea of the roasts are in line =
with my thinking, good job.
Ron Kyle
Anderson SC
rnkyle

36) From: EskWIRED
<Snip>
Would Pantone colors make any sense?  I thought that they had standard
colors pretty much wrapped up?
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37) From: C. Marley
EskWIRED wrote:
<Snip>
I think the first question that must be answered is "Is color a reliable
standard?" 
Just anecdotal, but if I roast Yemeni coffee, second crack starts while
the color is quite a bit lighter than the color of another coffee at the
same physical event.  And in the case of a dry processed coffee like
Yemen Mokha, the beans are very irregular in color at all stages, so
what beans are you going to select to judge color?  A chef judges the
"doneness" of a steak by the physical characteristics of the meat - how
compressible and resilient it is.  I just find that the physical
characteristics of the roast, appearance of the beans, exclusive of
color, and the timing of "cracks" are more important to reproducibility
than color.  I have no way to measure temperature accurately, so have
not considered it.  
Regards, Cathy
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38) From: John Abbott
Cathy,
First you really haven't watched guys cooking on a BBQ grill - we go by
color and smoke density.  Second - and more to the real point is that I
was really looking for a figure of merit on roasting identical beans.
Mike and I swapped beans and mine were clearly darker - so rather than
use a string of codes like light city, full city, aggressive full city,
etc. I thought that a color match might be in order.  Because Mike and I
roast at differing altitudes and ambients - the timing will be different
- but without trying to extrapolate a curve from a single point - I was
opting for another indicator. And for me - color would certainly be a
valid indicator.
On Tue, 2002-09-17 at 20:13, C. Marley wrote:
<Snip>
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39) From: Irene and Lubos Palounek
Please skip the following if not interested in comparing the color of real
coffee to the color in a PICTURE of coffee.
---
Kevin, I am sorry to say it and do not want to hurt your feelings, but your
statements that, when  comparing color of two objects with your eyes "the
lighting conditions are irrelevant - that's the purpose of using a
reference" is perhaps practically correct when comparing coffee to another
coffee -- but that statement is IMNSHO wrong when comparing a subject
(coffee) to a picture of that subject.  And that's what we are talking about
here, I believe: comparing real coffee to a printed color of coffee. In that
case we have Metameric Color Samples, that is a pair of colors which differ
spectrally but which yield the same or similar tristimulus values under at
least one set of viewing conditions, but different stimulus under different
light source, different viewing conditions. I do not understand, Kevin -- do
you disagree with that? Why?
Before I continue, let me say that I fully agree with Cathy and Tom -- the
coffee color is NOT that important for the purpose of homeroasting
consistency. As Tom wrote " ...I don't really think the SCAA roast tile kit
is that useful. I think there's no substitute for learning the look, smell
and sounds of the roast for different coffees, and a universal color kit is
not going to account for the variations in roast color...." I fully agree.
My apologies for wasting the bandwith and space. However, the subject of
comparing different colors under different light sources IS important when
dealing with *communicating* about the degree of roast of home-roasted
coffees; and thus I continue. I think many people on this list need a color
standard.  As John wrote, "...I'm going to keep looking for a standard -
there MUST be something out there." And the light sources ARE critical when
talking about colors and looking at color standards. Consider metamerism!
As Dan has pointed out, metamerism does not play any practical role when
comparing the SCAA coffee color samples with your coffee samples -- you are
comparing coffee to coffee.  But metamersim plays a big role when comparing
the color of roasted coffee with a picture of coffee - with color of
printing ink pigments that try to simulate the coffee color.
The Agtron machine was developed by physicist Carl Staub in order to label
the darkness of a roasted coffee bean. It uses near-infrared light to
measure the carmelization of the sugars. If "the lighting conditions were
irrelevant" for establishing the color of roasted coffee, he could have used
any inexpensive light source, correct? Why do people pay so much money for
the Agtron machine, if they could be using a reference and any light source?
Try two simple experiments.
Take some colorful fabric and take few pictures of it under several
different illuminations, let's say incandescent light bulb, fluorescent
"warm" light, morning sun, late evening sun. Take the fabric to your dark
room or to a photo-processing lab and match the colors or ask the technician
to match the colors of the prints to the original fabric. That should be
easy if the "lighting conditions are irrelevant", correct? Now take those
prints and the original fabric and compare the colors under the original
different illumination sources.  If the "lighting conditions are
irrelevant" -- why the colors of the fabric and the colors of the pictures
of the fabric do NOT look the same when illuminated different light sources?
Do a similar experiment with coffee. Roast it so that the beans match one of
the printed colors in the back of the Davis book. Now compare the beans and
the pictures under different lights -- why do they look different if "the
lighting conditions are irrelevant"? I have tried that experiment, and the
color differences between the real coffee and the pictures, when illuminated
by different light sources, were very noticeable to all the people.
Here is another view. If we had perfect CMY pigments, the people working
with color printing wouldn't have to add black ink as the fourth color. The
coffee itself does not have a black pigment in it, I believe, but the
pictures of it do. Are you saying that is wrong and that the Cyan, Magenta,
and Yellow pigments are the ONLY pigments needed for any color picture?
With which statements in Chapter 4 on Color Essentials in the "Photoshop 5"
book by David Blatner and Bruce Fraser do you disagree -- and why? If you
agree with all in that book -- how can you still claim that "the lighting
conditions are irrelevant" when comparing colors of the real subject and its
picture?
Many years ago, in his "Optics" published in 1704, Sir Isaac Newton observed
that color is not inherent in objects. Rather, the surface of an object
reflects some colors that are present in the light illuminating it and
absorbs all the others. We perceive only the reflected colors. If some
colors, some parts of the light spectrum are not present in the light
source, we cannot see those colors, those parts of the spectrum that are
missing from the light source.
Some colors which look the same may be composed of different mixes of pure,
one frequency color.
I think that most kids do the following simple experiment in early school
grades. Write some numbers using red ink on a piece of white paper.  Take
another white sheet of paper with nothing on it to use as a reference.
Everybody sees the difference. Now turn the regular lights of and illuminate
both sheets by red light.  Now both sheets look the same, they are all red,
the red-ink numbers have disappeared. How would you explain to them that
"the lighting conditions are irrelevant - that's the purpose of using a
reference" and that they MUST be seeing the red-ink numbers?
Read the Color Fundamentals on the www.pantone.com site or the introductory
chapters and the chapters on the Trichromatic system of any book on color
perception. Or search the net for Trichromatic System, Metamerism and
related terms. How can you state that "the lighting conditions are
irrelevant" -- any further explanation or any comments?
Try to convince Agtron that when they developed their Agtron E10-CP (and
other models of their instruments), they wasted money by including a
specific light source because "lighting conditions are irrelevant for
comparing colors".
Remember Land's "Retinex" theory of color vision (that is The Dr. Land,
founder of the Polaroid). Read about Mondrian color displays. Read the
instructions that come with The Munsell Books of Color (color reference
guides) or read the instructions that come with the GretagMacbeth charts.
Visit the GretagMacbeth Worldwide Headquarters in New Windsor, New York and
ask them about the computerized color matching software, color measurement
instrumentation and lighting systems, about metamerism. Try to convince them
that metamerism does not exist and therefore "comparing the coffee been AND
the color tile under the same lighting conditions ... makes the type of
lighting (unless VERY DIM) irrelevant." They have almost ninety years
experience in this field!
Talk to some people from Kodak or Fuji and try to convince them about your
theory "about photographs under sunlight at various times of day" and that
the temperature and spectrum of the light is irrelevant.
Well, sorry for wasting the bandwidth. It irritates me when incorrect
explanations (such as that, when comparing a subject to a picture of that
subject "the lighting conditions are irrelevant - that's the purpose of
using a reference" are stated as facts -- and get repeated -- confusing
people.
Regards, Lubos
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40) From: Dan Bollinger
<Snip>
Pantone colors are one of many specialty color systems. It was created for
printers and originally (I don't know if the color system has been expanded)
was only the colors you could create using printer's ink.  It is also called
PMS, Pantone Matching System.  Even if they were useful for coffee matching,
they are not readily availabe to all list members.
Another specialty color system is the one we all know, Agtron.  It was
created to color match in process food industry.  The Agtron color chips are
used for quality control in baking as well as coffee roasting.
There are others, but cost, availability or color system limitations present
problems.
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41) From: Arthur Lawson
The thing missing from this discussion of roast
"colors" is mention of the roast conditions that
brought the beans to some certain color. You can
arrive at the same finished color of beans through
fast and hot or cooler and longer roasts. You can, if
you want, apply low, prolonged heat and get a fairly
dark color in beans that are more dehydrated than
roasted, and sthat don't really taste like coffee at
all.
There are other useful observations such as the volume
expansion of the beans and the weight loss measured in
the finished product, that might help you change what
you do in your next roast,  but color evaluation isn't
very useful itself.
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42) From: C. Marley
John Abbott wrote:
<Snip>
I noticed that the color was different on the same beans roasted quickly
in the FR+ and slowly in the wok taken to the same crack stage.  How
would you account for that using color comparisons.  I couldn't.  The
color is obviously due to oxidation and caramelization of the sugars and
starches in the bean.  But it stands to reason that variations in the
speed of the process might produce different shades of color on the
surface even of the same beans. 
I don't know if paint chips would solve the problem.  Perhaps sample
beans exchanged would be more accurate descriptors of color, which along
with the flavor would be more meaningful.  If you picked matching beans
in a labeled sequence and sent one set to mike, along with a sample of
roasts suitable for grinding, corresponding to selected beans, then he
would be able to match the color in his own process to your sample set,
and send the results to you for taste comparison.
Regards, Cathy
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43) From: Mike McGinness
From: "Irene and Lubos Palounek" 
<Snip>
And the list went silent for over the past two hours...:-)
While Cathy's roast names and descriptions happen to very nearly perfectly
coincide with mine, full city doesn't mean the same thing to different
people. On this much we agree I think. The SCAA/Agtron Roast Color
Classification System was developed to address exactly that. Quote from SCAA
webpage "These eight industry standard disks are designed to enhance
consistency and assure that both roasters and their customers are in
agreement regarding degree of roast." Customer could mean very large
ordering firm, like Costco, placing an order for whole beans roasted to
Agtron 65 for instance. Me thinks you would need to get an order for say
10,000 pounds of roasted coffee roasted exactly how the customer expects it
to be roasted! Hence both ends of the purchase may very likey have the
Agtron tiles and same light source.
(I strongly suspect lighting is addressed in the SCAA/Agtron instructions
with the kit. Tom?)
In our case simply a desire to more accurately describe how our roast
compares to someone elses. Sight not seen. Roasting methods differing. While
variations in color matching do to light source is valid, I still believe
obtaining the tiles, then matching them with a paint sample, then comparing
grind to paint sample would probably be a more accurate way to describe our
roast to someone on the list than any other method we currently use.
Sure, someone says 30 seconds into 2nd crack. My question would be, how fast
is your temperature climbing during those 30 seconds, how long from onset of
1st crack to beginning of 2nd crack, how long from start of roast to onset
of 1st crack etc. Makes a huge difference in the final roast. 30 seconds
maintaining 2nd crack barely raising the temperature versus much higher
temperature agressively pushing towards a dark roast. Big difference in end
result. This is not conjecture. Reaching 2nd crack in 4min versus reaching
2nd crack in 15min makes a huge difference. You can roast at vastly
different speeds to the same final grind color, and will have vastly
different taste. Taste being subjective and the difference in taste greater
to some than to others. That said, color of grind would still only be one
indication of what a given roast might taste like... but a start.
MM;-)
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44) From: Gary Zimmerman
Lubos wrote:
<Snip>
Okay, admit it, Lubos: your last name is really "Ott", right?  You've 
mentioned the Ott-lite before, and are obviously very very pleased with 
it.  I'll take a look for one the next time I'm at Costco, but I wouldn't 
want to spend much more than $30 on it. (or "on ott").
Actually "getting it right" (judging the color) has never been an issue for 
me, since I don't compare results with anyone else.  I just do it for 
myself,, and I use consistent lighting (a small, high-intensity bicycle 
light, since I usually roast at night).  Even if the colors aren't true, 
that's enough for me to judge each roast relative to my other roasts that 
were similarly illuminated.
The lighting issue became very real to me when I looked at one roast the 
next morning, in daylight, and the beans seemed to match a different Ag 
number in Davids' book than they had the night before.  I don't know why 
the different lighting conditions would seem to affect the beans 
differently than the color plates in the book, but I couldn't argue with 
what I saw.  The difference was striking.  Now, even if I roast in the day 
time, I'll wait until the night and use my bike light illumination, just so 
I know the comparison to my other roasts is consistent.  (until the 
batteries run down, of course.)
I don't really do it judging properly anyway, as I just judge the whole 
beans, not the ground beans.  Sometimes when I don't crank quick enough the 
flat sides are darker than the round sides!
-- garyZ
WhirleyPop-drip(paper)-black
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45) From: Gary Zimmerman
C. Marley wrote:
<Snip>
I think this discussion started as a way to ensure that we could describe 
blends and roasts to each other unambiguously, rather than as a way to 
ensure we're using "first crack" and other descriptive terms 
correctly.  Since "city", "full city", "Vienna", "French", etc. are not 
really standardized terms (and have different "colors" depending on who you 
ask and on what bean you are roasting), it's not really something we can 
nail down, Agtron or not.
But if Mike says "I think Sylvanian beans are best when roasted to around 
45", we'd all have a better objective criteria for knowing generally what 
he's talking about.  It could never be exact, but it's probably a little 
more precise than using the named terms like "full city".
Different roasting techniques will produce a 45 color at different times 
too.  An evenly roasted bean at 45, if ground, will match a faster-roasted 
bean whose inside is lighter than its outside, with the colors averaging 
out to 45 when ground.  These beans would likely taste different, even 
though they share an Ag number.
Personally, I like using descriptions like "roasted just a few seconds into 
second crack", but that's probably going to differ too between roaster 
types and temps.
It's an art!
-- garyZ
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46) From: Dan Bollinger
<Snip>
differ
<Snip>
different
<Snip>
I used to have one of these!  Too bad I don't now, I'd upload a photo taken
by various light sources.
<Snip>
color
<Snip>
when
<Snip>
I roast by color and sound, mostly.  Others count or use temperature. Having
a simple, free comparison is a good starting point for any comparitive
discussion for a group that only communicates using typed words!
<Snip>
are
<Snip>
comparing
<Snip>
used
<Snip>
source?
I didn't know that!  Thanks.  Oh, and that reminds me.  When color experts
make comparisons, they always use a reference light source because they know
that 'colored' light effects color!
Lubos, you mentioned Munsell, it is my favorite color system.  I can imagine
a color and create the Munsell color-name in my head that's pretty close. I
wish more people used it, its really pretty easy to learn and more intuitive
than Pantone, and all the others.  Dan
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47) From: jim gundlach
On Tuesday, September 17, 2002, at 05:55 PM, Tom & Maria wrote:
<Snip>
I would not dispute this at all.  However, what I want is something that 
allows better communication  to someone else on the list.  Say two of us 
are wok roasting the Uganda AA for fourteen minutes to "a little into 
the second crack" and we are no where near each other geographically.  
It would be nice to say my ground coffee matches some tile or paint chip 
that we both could have and the other person would know if our roasts 
are the same or not.
Jim Gundlach
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48) From: Dan Bollinger
<Snip>
Tom, identifying the roast color IS part of the 'look' of roasting you
mention!  ;)  I don't think it is solitarily useful, either, but it is the
simplest, cheapest comparative we have outside of an Agtron or gas
chromatograph. Many of us are using thermocouples and monitoring temperature
(which I think is a very good method), but the expense will prevent many
home-roasters from going this route. Question, What is the definition of
City Roast?  Is it taste, time, temperature, color...?    thanks, Dan
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49) From: EskWIRED
<Snip>
That's what I do too.  I also use the amount of smoke as an indicator.  I
started roasting using an underpowered popper which needed to be totally
enclosed in a box, so sound, smell and smoke were my only feedback.
Having
<Snip>
I think that the bottom line, as has been pointed out in a zillion different
ways, is that no one system is adequate.  Color comparisons would help more
than they would hurt, so why not use them?  If they involved complicated or
expensive procedures, that would be a strike against color chips.  But they
don't.
I'm going to go to Sherwin Williams this afternoon and get a bunch of brown
chips.  I've got some Coffee Project Guat that I roasted yesterday, and this
morning's cup was pretty damn delicious.  I'll match it up and then try to
roast another batch to the same color, using my typical profile (hold them
at 375 degrees until they are a consistent color, then slow the fan so I get
a fast, strong first crack).  I'll try to stop them at the color shown on
the chip, and see what happens.
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50) From: EskWIRED
<Snip>
Do they carry SW at Home Depot?
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51) From: Ben Treichel
I don't think so. I was there yesterday and glanced around, but didn't 
see any for them.
EskWIRED wrote:
<Snip>
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52) From: Dan Bollinger
You'll have to go to a S-W store.  Let your fingers do the walking...

53) From: John Abbott
I guess then, if I want to maintain my CSA status I'll have to just
spring for a set of SCAA chips - but which four?  I think somebody
posted that already but as usual I wasn't paying attention.
Expressive/Driver personality can be such a pain!
John
On Tue, 2002-09-17 at 22:29, Dan Bollinger wrote:
<Snip>
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54) From: John Abbott
Except we did initially. Mike was using the BB profile, I was using the
HotTop profile and we can extrapolate a GREAT curve from that data.
On Wed, 2002-09-18 at 00:35, Arthur Lawson wrote:
<Snip>
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55) From: John Abbott
My Fault!!  This thread started when I was bemoaning the fact that I had
misunderstood Mike's definition of full city, and had overshot the
landing strip.  
All of the data had been carefully defined. We knew that we were using
beans from the same bag (ordering dates) we used more or less the same
process - Mike used the Black Bear profile, I used the preprogrammed
HotTop profile #6 (which it turns out is where Chang Yeu labels it
Vienna) We had both posted our time of day and roast duration. We both
had posted our beginning weights (but not the ending) and we had a
pretty good handle on the bean exchange.  
My discussion of color was in search of just one more additional piece
of information.  The color alone was never intended or suggested as the
measure of the roast.  But as people continued to drop into the middle
of the thread, they grasped at the obvious weakness of color as a
measure - and it is IF IT IS THE ONLY MEASURE.  But I was looking for
just one more additional piece of measuring data for a pretty good stack
of data already.
Hope that gets me off the BIG DUMMY LIST  and I'm sorry I ever brought
it up.  Golly Gee Whiz!!
John
On Wed, 2002-09-18 at 00:36, C. Marley wrote:
<Snip>
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56) From: John Abbott
I think this is probably going to be THE answer to all this. I already
have a sample of Mike's roast - two beans and two fine ground beans -
under vacuum sealed plastic.  Its a beginning for me - but now if I want
to do this with Scott or Dan then we have to exchange samples first and
calibrate and then go on from there.  My hope was something we could all
access. But its probably not practical.
John - sticking with setting 5 for all exchanges :O)
On Wed, 2002-09-18 at 00:36, C. Marley wrote:
<Snip>
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57) From: Irene and Lubos Palounek
How much does the color of roasted beans change with time? If nobody here
knows the answer, I will try to match freshly roasted beans to a picture of
the color and try it again after lets say six months and a year and ...
(under the same light source, of course :-)
I hope that the printed picture does not change much during that time
period.
So much to learn, so little time.
Lubos
P.S.
I heard that some people fear retirement as they are afraid they will be
bored.  How is that possible?
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58) From: Dan Bollinger
I read that beans continue to grow darker with age, making the useless as
their own color standard a few weeks after roasting.
<Snip>
of
<Snip>
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59) From: Kevin DuPre
Mike,
This is the best and most sensible post I've seen so
far on this thread, and I am in full agreement.
Someone with Agtron disks finding color chips which
match under a fairly balancedbright light source (read
poor-person's Agtron references).
If we all could get the same color chips by the same
manufacturer and view them in comparison with our
roast under a bright light source, we could all be
comparing apples for apples (assuming we are not
photographing the roast and comparing that to the
chips :-)
I also agree that roast color is not definitive in and
of itself - that is the whole point of the propriety
of roast profiles by different roasters and what
largely differentiates one roaster's product from
another.
I do assume that light source is covered under the
Agtron disk instructions, but knowing what I know
about precise light sources, the price of that could
easily exceed the cost of the Agtron disks by hundreds
or thousands of dollars if a specific one needs to be
used.
Regards,
Kevin
<Snip>
<Snip>
=====
--
Kevin DuPre
obxwindsurfhttp://profiles.yahoo.com/obxwindsurf"The real voyage of discovery consists not in seeking new landscapes but in having new eyes -- Marcel Proust"
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60) From: Angelo
I seem to remember the last time we had this discussion, someone suggested 
using commercially roasted beans as a reference ,which is pretty cheap and 
readily available. We might have some problems with our un-American 
brethren as to availability. But, hey, that's what happens when you choose 
not to live here.. (j/k). I'm not familiar with a brand of roasted beans 
which is international. However, I don't think Sherwin-Williams is either.
I guess we would have to set a time frame, since beans tend to darken as 
they age. Although, the beans are probably so stale that they more than 
likely have  reached their "permanent" color...Whatcha think?
Angelo
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61) From: dewardh
Gary:
<Snip>
at Costco, but I wouldn't
want to spend much more than $30 on it. (or "on ott").
Actually, you don't need to get an "Ott" light to get the "Ott" effect . . . 
"Ott" is far more marketing than anything else.  I looked at the "Ott" light 
available at CostCo a while ago . . . it had a "major manufacturer" 6500K 
"color corrected" fluorescent tube in it (Sylvania, if I remember correctly) . 
.. . nothing you can't buy at any well stocked hardware or lighting store (for a 
lot less than "Ott" prices).  Color temperature and spectral matching are 
issues of common currency in photography and all the graphic arts, as well as 
among indoor growers and the acquarium and vivarium trade.  Lubos is quite 
correct . . . color "matching" is *much* more complex than just comparing bean 
to tile (even under the most "controlled" lighting) . . . without a 
"standardized" light source there can be no "standard" color . . . be it tile, 
or paint sample, or whatever.  And even then . . .
<Snip>
me, since I don't compare results with anyone else.  I just do it for
myself,, and I use consistent lighting (a small, high-intensity bicycle
light, since I usually roast at night).  Even if the colors aren't true,
that's enough for me to judge each roast relative to my other roasts that
were similarly illuminated.
I use a Maglite myself (while in the roaster) . . . and daylight when it's 
"done".
Deward
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62) From: Ted Kostek
<Snip>
The color of sunlight varies with time of day and cloud condition.
tmk
--
Ted Kostek
765 494 2146 (desk)
765 494 1489 (engine room)
765 494 0787 (fax)
"Always keep in mind that your own resolution to succeed is more important
than any other thing."  Abraham Lincoln
<Snip>
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63) From: Mike McGinness
Has everyone read the Sept-Oct Tiny Joy? (Comes with all greens orders of
20# or more, don't know about smaller orders:-) Tom did a good full front
page right up on just his topic...
MM;-)
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64) From: John
NOPE!! And my order qualified.  I got the "Oops Generic" because they
ran out of "real" newsletters. I guess I'm not really CSA enough :O)
On Thu, 2002-09-19 at 03:07, Mike McGinness wrote:
<Snip>
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65) From: Les & Becky
Well Gang, thanks to my mother's genetics I have a rare color blindness
called chromatic color blindness.  It can only be inherited by males of
mothers of Irish decent.  My mother being full Irish made me a good
candidate.  Even among us it is one in fifty thousand.  What does this mean?
Throw down 4 shades of those color chips and they all look the same to me!
I sure am glad that I roast by time, crack, and smell.  One of the strange
things about this color problem is that I can see all colors, my brain just
doesn't process shades like other folks.
I can still roast and brew a fine cup of coffee!
Les
Roasting in S. Oregon
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