HomeRoast Digest


Topic: A different approach for a roasting profile (4 msgs / 127 lines)
1) From: Douglas H. Boutell
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Hope this will help others.
Recently I have been trying a different roasting profile with my Fresh
Roast Plus. I have been very satisfied with the info
on the Homeroast digest on the rate of climb, etc.--  but I like to
tinker with different ideas. I have a dual thermocouple
data logger  and decided to measure the input temp on the bottom of the
roasting chamber and the output  temp approx 1/2"
from the top of the green beans. I found out that at the beginning of
the 1st crack(400 F)  to the end of the roast, their 
was about a 70 degree change in temp.  I  wanted to see  what the  
changes in  taste would  be if I kept a more even roasting temp
from 400 to the end of the roast. I vary the fan speed to control the
temp differential that I have chosen .
 I have only had time to test  Panama Elida, Kenya Mika, and  Brazil
-Fazenda Vargem.
Some prelim notations : Their has been an overall sweeter taste to the
beans , a little more body , and complexity . On the  my last batch of 
 Panama Elida , I by accident hit a very good sweet spot  on the
roasting  WHAT A HUGE CHANGE  in taste and flavor. Bad news 
for me because I will be trying to find that elusive  sweet spot in the
other greens that I have. Oh!  how to drive the small coffee roaster
crazy.
New arrival of Elida this week so I can test more, buy more green beans
and drive myself deeper  into the Bean House. But  good for Tom &
Maria.
Jim Schulman was helpful and sent me a  link to Swiss Tech School  that
had a published paper in PDF format (160+ pages) on  coffee roasting.
Hope it will help others.
http://e-collection.ethbib.ethz.ch/cgi-bin/show.pl?type=diss&nr620 
Back to my testing.
Doug

2) From: Jim Schulman
Hi Douglas,
Thanks for posting this.
As I said when you mailed me, I think this is potentially an 
important insight. Many of the benefits of a slow roast may 
infact derive from the fact that the drivong temperature (in an 
airroaster, the air coming in) is not much hotter than the beans 
themselves. One thing in the roasting dissertation was that 
roasts were improved if the inflow air temperature was ramped up 
slowly.
One could potentially distinguish this effect from time/ bean 
temperature ones by speeding the roast with lower temp air by 
blowing through more air, increasing the convection rate.
Jim
On 22 Sep 2003 at 18:06, Douglas H. Boutell wrote:
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3) From: miKe mcKoffee

4) From: Ed Needham
Thanks for the link.
Now for the time to read it...
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Ed Needham
To Absurdity and Beyond!
homeroaster ... d.o.t ... com
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