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Topic: Three ways to ruin a roast.... (13 msgs / 408 lines)
1) From: Tom Gramila
Hi All,
	I have been making some improvements on my computer controlled
roaster and have had occasion to experience a couple of "don't do this to
your roast, or you will regret it" profile features.  These have occured
as I have tried various approaches to letting the computer vary the
airflow on my poppery -- which tends to cause some problems for my control
algorithm, designed to control the rate of rise of the bean temperatures
directly.  Anyway, these 'must avoids' have been mentioned, if I remember
correctly, by others (MM, JS, etc), but it has been, umm, very interesting
to experience them firsthand.....
	The beginning of the roast - bean stabilization stage:  Beans are
heated up to about 225F.  The lore that I had learned was that you want to
give the beans a chance to thermalize here -- not much chemistry happens,
but reaching a uniform temperature in the beans here affects their thermal
conductivity, permitting a much greater uniformity for the rest of the
roast.  I was suprised that the roast can be really dulled by spending too
long here, so some chemistry has to be happenning.....  My best roasts
happen with about a three minute ramp to 225, and a 30 second hold.  This
is not far from what I think Mike M suggested long ago.  Faster lacks
uniformity, but five minutes is too long!
	Post first crack:  about three minutes spent after first crack to
the finish temperature really does give a nice character, as Jim S has
been asserting.  Much faster (2 min) and the roast is sort of coarse, and
much longer (4 min) and the roast becomes sort of harsh.  This is the
hardest part of the roast for the computer to control, so I have had a
chance to "explore" a bunch here....  I think that this can be healed, to
some degree, by resting the beans.
	Right at first crack.  This is a tricky part of the roast as well,
at least in a hot air roaster, since you want to slow down to achieve that
post first crack 'tempering'.  Backing off on the heat too quickly,
however, can cause a dip in the temperature of the hot air that is
roasting the beans.  Even the slightest cooling of the beans at this
point, even for a very short time, really does make a noticable
difference, -- yuck.  I'm not sure who to attribute this to, it's
mentioned on a bunch of web pages, but it was suprising to see how
'fragile' the quality of the beans are at this stage in the roast.
	Comments or suggestions???  What do you think?
-- 
				Tom G.
Proof of Principle Computer Controlled Poppery Coffee Roasterhttp://home.columbus.rr.com/thegramilas/coffee/roaster.html

2) From: byellin
Sorry for top-posting, but it's a long way to the bottom...
I have come to pretty much, the same conclusions: one to two minutes to about 
250 or 260 but not longer, another one to three minutes to about 300 but never 
longer, (time depends on the bean type and other conditions); another 2 or 
three minutes to first crack and in general, never let the bean temps go 
anywhere but level or up at any time, and finally, 3 to 4 minutes between 1st 
crack and the end (occasionally shorter or longer for a particular bean or 
desired "effect" but not in general).
These guidelines keep receiving confirmation from various sources.
Bob Yellin
Quoting Tom Gramila :
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3) From: Ken Mary
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Sigh. I guess it is time for a brief delurk and "troll" post about my fast
roasting. If your roast takes longer than 3 minutes, you are wasting time.
:-)
Seriously, I just made my absolute best roast of all time of any coffee. It
was Sumatra Mandheling Grade 1 taken to approx city+ in 2 min 35 seconds.
The brew aroma was so complex that I wanted to inhale it all. You know a
good roast from the instant the first sip touches the tip of the tongue.
Within nanoseconds, I was in Nirvana. And this was one hour post roast.
The roaster is a hybrid of a Presto heater in a Proctor Silex pumper. The
heater wire is shortened and stretched to cover the circumference of the
mica to prevent hot spots. The fan is run by a 25 v transformer at full
speed. What could be more simple, fan on, dump beans, heat on, heat off
about 2 1/2 minutes later, cool about 2 minutes in the popper.
I know this fast roasting flies in the face of conventional wisdom, but at
least in my book, taste rules. I have other roasters with inherent or
variable profiles from 5 to 15 minutes, so I do also appreciate the slower
roasts. But none have the impact of brightness and complexity that fast
roasts produce.
Do not expect any replies from me soon, as I am off on another trip.
--

4) From: gin
don't be sorry, always top post...
g
At 03:27 AM 6/27/2004, you wrote:
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5) From: Simpson
*********** REPLY SEPARATOR  ***********
On 6/27/2004 at 8:04 AM Ken Mary wrote:
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Some time ago an altie posted that he had spoken with Michael Sivetz who
suggested he 'slam it on through' first crack. I've googled like crazy but
can't find the original quote. Sorry.
Here's an interesting post from Tom, though:http://makeashorterlink.com/?V186529A8Ted
-----
"Before you criticize someone, you should walk a mile in their shoes. That
way, when you criticize them, you're a mile away and you have their shoes."
(author unknown)

6) From: Jim Schulman
On 27 Jun 2004 at 2:57, Tom Gramila wrote:
<Snip>
Ted mentioned a quote from Sivetz here. I've heard it as well, 
Iirc, a post of mine about a year and half ago, where I tried 
various manual profiles on a variac. The ones where I slowed 
down during the first were uniformly horrible.
BUT ... that was way before I had good temperature monitoring 
and control. I may have been dropping the temperature at this 
point, which really will kill a roast. A steady but slow rise 
through the first can work wonders for some beans, like Mike's 
trick for last year's "Ueber"-Kenya Mika, which had harsh roast 
tastes that were mellowed by this slowing down. 
Jim

7) From: Brian Kamnetz
At 02:57 AM 6/27/2004 -0400, you wrote:
<Snip>
Hi Tom,
I am interested in knowing what you refer to as "first crack". Do you mean 
the very first couple cracks, the "outliers", or perhaps after achieving a 
rolling first crack, or after a rolling crack followed by cessation of 
cracks, etc.
Thanks,
Brian

8) From: miKe mcKoffee
BB profile influence and other profile comments below...

9) From: miKe mcKoffee
Bob, excellent air roaster profile guidelines. Much better reply than a
lengthy dissertation style some might post, oops, was that was me:-)
Kona Konnaisseur miKe mcKoffee
URL to Rosto mods, FrankenFormer etc.http://mdmint.home.comcast.net/coffee/Rosto_mod.htm

10) From: Tom Gramila
On Sun, 27 Jun 2004, Brian Kamnetz wrote:
<Snip>
Hi brian,
	I actually start counting at 405 to 410 degrees, at which point
first crack is generally just finished.  I am usually running 20 or 25
degrees per minute before that, so bean type variations in first crack
onset of a few degrees does not make a big difference in my timing.  
First crack usually lasts for less than 30 seconds in my rig, sometimes
shorter. There are generally few outliers if I have pre-heated (the
section up to 225) correctly.  So I guess the simple answer is: from when
its about over....
			Tom G
Proof of Principle Computer Controlled Poppery Coffee Roasterhttp://home.columbus.rr.com/thegramilas/coffee/roaster.html

11) From: Tom Gramila
Hi Mike!
	Thanks for the detailed response. My Initial comments are 
'embedded', I will have to add more later when I have a chance to
look carefully at the profile you listed and discussion of the near first
crack section.... 
On Sun, 27 Jun 2004, miKe mcKoffee wrote:
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				^ Wow!
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	If you held at 225 did the time to 310 lengthen, or did you speed 
	the next part to keep 4 minutes??
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	This is interesting, I wonder if there are two conflicting
concerns here.  If I go as fast as you to 225, I cannot get an even roast,
and things taste bad.  If I spend too long here, I find, as you have, that
things taste flat.  But I generally go faster after 225, about 40 per
minute, so that I am at 300 in 5 or at most 6 minutes, which is not sooo
far from your timing.  Perhaps optimal is to go as fast as one can here
while keeping things even....  I dont have enough fan "oomph" to do the
225 bit much quicker....  Maybe after I replace my fan motor, as I have 
been hoping to.
	(I have also noted that during my 225 hold (only 30 seconds), the
amount of heat that needs to be added to the beans to maintain a uniform
"measured" temperature ends up dropping -- which indicates, I think, that
heat is still diffusing into the beans, and thay are not uniform in
temperature internally until the end of the hold ....)
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	I count from the end of first, but first only lasts 30 seconds or 
	so for me, so I'm 3-1/2 from the beginning, again close to your
	target.
<Snip>
	I know I have some old kenya somewhere, I'm hoping that its mika 
	so that I can try that out....
<Snip>
	Tom G.
Proof of Principle Computer Controlled Poppery Coffee Roasterhttp://home.columbus.rr.com/thegramilas/coffee/roaster.html

12) From: Pecan Jim Gundlach
I'm not Tom, but I don't count the early outliers as the first crack.  
I usually use the first outliers as an indicator to increase the heat 
and speed up the first crack.   You can think of it as a normal 
distribution, both tails have cracks that are few and far between, The 
middle 95% is what we are interested in.
    Jim Gundlach
On Jun 27, 2004, at 1:34 PM, Brian Kamnetz wrote:
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13) From: Brian Kamnetz
Hi Jim,
Your comment, "I usually use the first outliers as an indicator to increase 
the heat and speed up the first crack," is interesting and likely very 
helpful to me. I have been trying to avoid burning my roasts and have taken 
first crack as in indication to LET UP on the heat! My thought has been 
that I should be stabilizing, not increasing, the heat at this point. I'll 
be roasting again in a few days and I will keep this interesting tidbit in 
mind.
Thanks!
Brian
At 04:25 PM 6/27/2004 -0500, you wrote:
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