HomeRoast Digest


Topic: Gene Cafe observation... and question (4 msgs / 171 lines)
1) From: Donald Varona
On an earlier post, someone noted that they had a hard time hearing 
first crack in the GC roaster, but second crack was louder.  This is 
opposite from what literature says about the intensity of each crack.. 
but with my own Gene Cafe, I have an explanation, based on  experience.
While the beans are still green, they are denser and more like pebbles; 
they tend to clack along the glass container loudly.  It is harder to 
distinguish the first crack from the bean-clacking during this phase.  
In my experience (with one bean so far), this happens at around 11:30 
into the roast at full-blast 482F.
After first crack, they are less dense and make less impact on the 
glass.  Also, since they've expanded in volume, they don't have as much 
room to move around, and this too reduces noise.  The second crack is 
much easier to hear then.  This seems to happen around 16:45 after a 
first-crack drop to 460F.
So I'm still experimenting and learning the machine.  I've done 3 roasts 
so far, from a lesser to a fuller roast.  I've been using the same bean 
(Columbia Tolima Planadas) from a 5# bag to reduce the variables... 
which leads to my question.
Someone else mentioned that they removed the chamber divider from the GC 
to allow for easier cleaning.  I can see that this will need to be done 
before long, as I already have a slight clouding of the glass from use.  
However, I never did see anyone say how the piece was actually removed, 
and it looks like it wasn't intended to be removed.  I would appreciate 
any clearer explanation on how to accomplish this.
And if you're wondering how my roasts are turning out, I'll have to say 
I'm not super-impressed so far yet.  The first roast was not long 
enough, so was quite acidy; the current one is too dark for my taste (I 
went all the way through second crack) but is still pleasant enough.  
The second one was nice but freshness was the main thing going for it.
This all might be because of the bean I'm using.  I had normally been 
buying from a local roaster who claimed to have daily-roasted beans, so 
perhaps I'm already familiar with what "really fresh" coffee is.  But 
then I've also tended toward fuller-bodied coffees like Sumatra, and I 
haven't opened that pack yet (also got the 8lb pack from SM :-).
Although I'm not super-impressed (no real "WOW"-factor), I am pleased.  
I know that the coffee is fresh, and I roast only what I'll use in a few 
days, and that counts for a lot.  I'm also still trying to settle on the 
right settings for various things-- grinds for drip vs. aeropress vs. 
moka, temps on roasts and beans, coffee weight vs. water-- so there's 
lots more fine-tuning to come!
--dv

2) From: L. Michael Fraley, MD
Hi Donald.  First let me say I have no experience at all with a Gene 
Cafe.  However, based on my experience with other roasting methods 
(pan, IR2 and Hottop) I think you might be on to something.  With the 
pan roasting first crack did indeed seem loader to me and easy to 
distinguish.  However with the Hottop, I am having a similar experience 
to what you describe.  And then with the IR2 it was not too easy to 
hear either crack.  I have noticed, though, that with experience, I am 
beginning to be able to hear the cracks better with all the roasting 
methods I use.  And, naturally, I do not depend solely on sound to 
determine roast anyway.  Happy roasting!
Michael
On Feb 1, 2007, at 9:42 PM, Donald Varona wrote:
On an earlier post, someone noted that they had a hard time hearing 
first crack in the GC roaster, but second crack was louder.  This is 
opposite from what literature says about the intensity of each crack.. 
but with my own Gene Cafe, I have an explanation, based on  experience.
While the beans are still green, they are denser and more like pebbles; 
they tend to clack along the glass container loudly.  It is harder to 
distinguish the first crack from the bean-clacking during this phase.  
In my experience (with one bean so far), this happens at around 11:30 
into the roast at full-blast 482F.
After first crack, they are less dense and make less impact on the 
glass.  Also, since they've expanded in volume, they don't have as much 
room to move around, and this too reduces noise.  The second crack is 
much easier to hear then.  This seems to happen around 16:45 after a 
first-crack drop to 460F.
So I'm still experimenting and learning the machine.  I've done 3 
roasts so far, from a lesser to a fuller roast.  I've been using the 
same bean (Columbia Tolima Planadas) from a 5# bag to reduce the 
variables... which leads to my question.
Someone else mentioned that they removed the chamber divider from the 
GC to allow for easier cleaning.  I can see that this will need to be 
done before long, as I already have a slight clouding of the glass from 
use.  However, I never did see anyone say how the piece was actually 
removed, and it looks like it wasn't intended to be removed.  I would 
appreciate any clearer explanation on how to accomplish this.
And if you're wondering how my roasts are turning out, I'll have to say 
I'm not super-impressed so far yet.  The first roast was not long 
enough, so was quite acidy; the current one is too dark for my taste (I 
went all the way through second crack) but is still pleasant enough.  
The second one was nice but freshness was the main thing going for it.
This all might be because of the bean I'm using.  I had normally been 
buying from a local roaster who claimed to have daily-roasted beans, so 
perhaps I'm already familiar with what "really fresh" coffee is.  But 
then I've also tended toward fuller-bodied coffees like Sumatra, and I 
haven't opened that pack yet (also got the 8lb pack from SM :-).
Although I'm not super-impressed (no real "WOW"-factor), I am pleased.  
I know that the coffee is fresh, and I roast only what I'll use in a 
few days, and that counts for a lot.  I'm also still trying to settle 
on the right settings for various things-- grinds for drip vs. 
aeropress vs. moka, temps on roasts and beans, coffee weight vs. 
water-- so there's lots more fine-tuning to come!
--dv

3) From: Frank Parth
Donald,
I was just one of several people who said they couldn't hear first crack in the GC, but could hear second crack. 
I hadn't thought about it before, but your explanation sounds reasonable to me. There's no question that when the beans are still green they make a lot of noise banging against the glass. 
One thing I've started doing is ramping up the heat slowly based on profiles posted by Eddie. I'll give it five minutes at 320 degrees, then another five minutes at 420 degrees before bringing it to 456 for the final blast. Since I started doing this I've noticed that I can hear a faint first crack. That now makes sense if I've already expanded the bean so it's not so dense.
Thanks for the analysis.
Frank Parth
On Thursday, February 01, 2007, at 06:43PM, "Donald Varona"  wrote:
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4) From: Eddie Dove
Frank,
Let me know how your profiles work out for you.  I have noticed that if I
get the profile right, beans that I have had a difficult time hearing 1st
crack, will suddenly erupt in an undeniably audible 1st crack ... sometime
rolling like the middle of the bag of popcorn in the microwave.
Eddie
-- 
Errare humanun est - sed perseverare diabolicum
My Home Coffee Roasting Blog and Profiles for the Gene Cafehttp://themeyers.org/HomeRoast/On 2/3/07, Frank Parth  wrote:">http://southcoastcoffeeroaster.blogspot.com/Sweet Maria's List - Searchable Archiveshttp://themeyers.org/HomeRoast/On 2/3/07, Frank Parth  wrote:
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