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Topic: mcKoffee: I have another question ... (7 msgs / 187 lines)
1) From: Eddie Dove
miKe wrote:  "I've found the early pre-tanning stage just as important as
the start of 1st to end of roast stage. Too short time before tanning can
lead to grassy/green aftertaste while too long inhibits good caramelization
latter on I believe.  I use about 4min drying stage (to my 300f). Then
there's the main setup ramp tanning through browning. It's amazing how
varying the ramp rate will alter the cup, same total roast time. Have done
many comparison roasts in the past. Most Kona I've settled in on about
25f/min ramp tanning to start of 1st. Now I slow it down to 15f/min for a
couple min then 10f/min final ~minute and a half my ~445f end of roast
usually about 11:30. (which is about 5f before anticipated 2nd). Unless it's
Kona Peaberry then a different overall faster profile usually about 10 to
10:30min. Cooling target 2min to 125f or less."
If I understand correctly, what you describe above is a constant ramp upward
toward the end without throttling back.  Is this correct?  Do you only do
this for Konas or a certain type of bean?
Respectfully,
Eddie

2) From: Ken Mary
I cannot speak for Mike, but reducing the heat after first is necessary to
avoid running too fast toward second. You need enough heat input to prevent
the bean temperature from falling. A falling temperature after first will
not ruin a bean but will kill the brightness. Between those extremes, it is
up to you to decide your preference.
All roasters have a different response to heat input. A heavy wall drum with
a large bean load cannot respond quickly to changes in heat. You have to
anticipate the heat requirement minutes ahead of time. Fluid bed roasters
with a light bean load can respond in a few seconds.
Profiling does not have to be babysitting a roast and tweaking the
temperature every few seconds. With my toaster oven drum roaster, I like a
constant heat input from cold start to finish for dry process Brazils. I set
the heater at the wattage requirement for the intended finish ramp, then
leave it untouched during the entire roast. The initial heatup is slow until
the elements reach maximum temperature. The maximum ramp is 18C per minute
at 80C bean temp 5 minutes after startup. At 200C just before first, the
ramp has declined to 9C per minute, about 16 minutes after startup. There is
a brief decline to 7C during first then a return to 9C at the finish at
about 18.5 to 19 minutes total. This is a quite fast finish ramp, so I
terminate the roast near 220C bean temperature for a city level. This
"profile" results in enhanced sweet chocolate flavor and preserves what
little brightness there is in the bean.
With wet process beans, I do a faster heatup, but then stall the temperature
near 125C for drying. After that it is full heat to 180C where I reduce the
heat in one or more stages to achieve the result I want for the particular
bean.
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3) From: miKe mcKoffee
	From: homeroast-admin
[mailto:homeroast-admin] On Behalf Of Eddie Dove
	Sent: Saturday, December 02, 2006 3:22 PM
	
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important as the start of 1st to end of roast stage. Too short time before
tanning can lead to grassy/green aftertaste while too long inhibits good
caramelization latter on I believe.  I use about 4min drying stage (to my
300f). Then there's the main setup ramp tanning through browning. It's
amazing how varying the ramp rate will alter the cup, same total roast time.
Have done many comparison roasts in the past. Most Kona I've settled in on
about 25f/min ramp tanning to start of 1st. Now I slow it down to 15f/min
for a couple min then 10f/min final ~minute and a half my ~445f end of roast
usually about 11:30. (which is about 5f before anticipated 2nd). Unless it's
Kona Peaberry then a different overall faster profile usually about 10 to
10:30min. Cooling target 2min to 125f or less." 
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ramp upward toward the end without throttling back.  Is this correct?  Do
you only do this for Konas or a certain type of bean?
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Constant ramp rate from tanning to start of 1st yes (ie ramp rate of bean
temp rise not applied heat temp). Usually between 20 to 30f/min depending on
the bean. 
My current "main" profile (using past couple years). 
Note: first batch of session I pre-heat the Rosto to ~250f then cool to
~100f, same approx cooling temp as cooled batch. "Over sized" 1/2# batches.
(Compared to stock Rosto 1/4# desinged batches)
Target temps:
200f @ 1min (heater voltage usually 120 to 125v start, dropping to 102 to
108v ~150f ~25sec point depending on ambient)
250f @ 2min (usually maintaining same 102 to 108v or slightly adjusting)
275f 3min  (usually couple volt bump to heater)
300f 4min (usually another couple volt bump, tanning stage begins)
325f 5min (4 to 6v bump, now up to 110 to 118v to heater depending)
350f 6min (often up to 120v to heater by now, browning stage begins)
375f 7min (sometimes need more heater power, sometimes not depending on
ambient)
400f 8min (usually need 2 to 4v more to heater, 1st crack usually about now,
often drop heater voltage 1 or 2v)
415f 9min (usually a couple v heater voltage bump back up)
430f 10min (usually backing heater v off a few)
440f 11min City+ (often continuing dropping voltage a couple v, depending)
445f 11:30min LFC (very common finish point for Kona, Centrals, Island etc)
450f 12min FC (early 2nds) 
455f 12:30 FC+ (common Sumatra finish, used to go lighter but found like
Indo's a bit darker, a few seconds of 2nd)
460f seldom go this high bean temp.
For my espresso blends I usually go to 450f but a slower mid and finish but
same start ramp, ~15min total roast. Use 20f/min tanning to start of 1st
ramp, straight 10f/min 400f to 440f, then 5f/min 440 to 450f end of roast.
This very slow finish ramp 2nd kicks in a bit earlier.
I used to routinely use a finish "hold at final temp" for 30sec or so but
don't now, though still do at times, depends on what the beans tell me they
want from smell, sound, look etc.
Kona Konnaisseur miKe mcKoffee
URL to Rosto mods, FrankenFormer, some recipes etc:http://mdmint.home.comcast.net/coffee/Rosto_mod.htmUltimately the quest for Koffee Nirvana is a solitary path. To know I must
first not know. And in knowing know I know not. Each Personal enlightenment
found exploring the many divergent foot steps of Those who have gone before.

4) From: Eddie Dove
Mr. mcKoffee,
I want you to know that I truly and sincerely appreciate you taking the time
to entertain and answer my questions.  I am taking this information and
applying it to learning and in the last week I have gained even more
understanding and applied it to my roasting yesterday.  Again, I really
appreciate you sharing this information and the reasoning for such.
Sincerely,
Eddie
On 12/3/06, miKe mcKoffee  wrote:
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5) From: Michael Dhabolt
miKe,
Thanks for the profile......always learning.  One comment to those that
aren't instrumented to this level.......an increase in voltage at a higher
bean temperature does not necessarily mean an increase in heatup rate as
compared to a corresponding increase in volatage at a lower bean temp.
In response to comments about slowing the roast after 1st......I have found
that slowing at the beginning of first is beneficial (after prompting by
several long time roasters).
Mike (just plain)

6) From: Eddie Dove
Ken,
Thank you for the information.  This is helpful.
Eddie
On 12/3/06, Ken Mary  wrote:
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7) From: Marc
I also use a PID'd Rosto. Here are 3 profiles: miKe mcKoffee's as described
above and 2 that I use.  You can see that miKe reaches 300F in 4 minutes
while I'm closer to 5. His total roast time is 12 mins vs my 15 min (note I
made a typo on the graph fro miKe's time to FC). I also roast smaller
matches (6.5 ozs as opposed to 8 ozs. - I cannot seem to get 8 ozs to move
enough in my Rosto and the 6.5 oz batch gives me 5 roasts per 2 lb bag).
I'm going to give miKe's profile a try but I thought it might be helpful to
see the graphs...http://coffee.nccs.biz/graph.jpg-Marc
On 12/3/06, Eddie Dove  wrote:
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