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JackH
OfflineAdmin
· 07/04/2020 10:27 AM
Happy 4th of July! jazzyhands

JackH
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· 06/24/2020 7:58 AM
@Mark McCornack, Please post your question in the forum.

Mark McCornack
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· 06/15/2020 9:28 PM
Hi! Looking for a legacy inlet temp sensor on 13 yr old Gene Cafe. It seems they've changed it and now you need new mother board and new sensor. Any ideas where I can find compatibile old one? Mark

Samaniego
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· 06/09/2020 6:39 PM
Wich thermometers Can i buy for my roasting machine compatible with usb or macbook?

JackH
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· 06/05/2020 5:38 PM
peveleth, It is better if you start a post in the forum with your question. These shouts go away in time.

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Drying Phase in my Gene Cafe
ML
hazbean - I loved the fact that you drilled holes in your new roaster!
Ryan - Thanks for the help, buddy

As far as pre-heating goes: isn't starting from cold having the GC temp consistent?
let's pretend -
depending on where you're at room temp beans are anywhere from 40* to 85* (we're pretending, you see)
you place the beans in a warmed-up Estopped GC
once you've restarted the internal drum temp is different for each user because of a few factors but we can all agree it's warmer than cold in there
you set the controls for a warming phase let's say 300* for 5 mins
whatever the BMT is after that 5 min yellowing interval no one knows but the beans are whatever temp they are and you begin your roasting profile and you're satisfied, more than satisfied with the resultant roast
If you begin at cold and set the controls to 300* for 5 mins you might find the beans are indeed yellow at this point, perhaps less time spent at yellow but just as yellow as the bean can be, cowardly bean, you begin you're profile and are/are not happy with the resultant roast
reaching yellow beans at about more or less 5 mins in a pre-heating drying phase seems to be the sweet spot for the GC roaster,
anyone's everyone's GC roaster?
and there seems to be many ways to get there depending on the home roaster

There are many ways to skin the bean with this here machine and find that shiny glean on the surface of that there bean and grind the results into a savory grin but don't spill a drop because it's the last of that there crop...
 
Steve Egge
This was my "experiment" weekend.
I bought some beans from SM - the "Panama dry process gone awry" cheap beans and used them to test out some stuff.

All roasting stopped by E stop .. shaking the beans to the left side ... standing the drum on the drum holder, opening the lid, and inserting a thermapen into the bean mass and "stirring" in a figure of 8 fashion, recording the maximum bean temp. No beans were used twice. (I prevented damage to the Gene by inserting another roaster drum and hitting cooling phase).

All were done with preheated drum to 400°F with 227 grams of beans ...

Warm Beans at 350°F x 4 Minutes ... BT 238°F wt 222.1 gm = 2.16% wt loss
Warm Beans at 350°F x 5 Minutes ... BT 254°F wt 220.9 gm = 2.69% wt loss

So during this "drying phase" if you will ... heat is still being applied to the beans and the temps are rising ... although slowly throughout this phase ... that is they are not totally stalled (although not heating up as fast as if you were at 482!)

This reflects my experience with a bean I was having trouble with ...
I previously roasted Guatemala Huehuetenango Finca Rosma with a 4 minute drying period trying for a lighter roast and found it had a bold lemon flavor .. like it was under roasted.
So I next tried it with the same profile but extended the drying period to 5 minutes at 350 (instead of 4) and despite ending up with less bean wt loss by a percent, that is to say it was a lighter roast, there was less lemon grass flavor ... more of what I would expect it to taste like.
(basic profile stolen from Drew - Army Coffee)
preheat 400
warm beans 350 x 4 minutes
482 till 40 sec into first crack
Then lower to 456 till you stop roast.

BTW I'm pretty happy with the thermapen (a bit pricy but I can use it for other things) and it is quick to temp and seems fairly accurate. Much more responsive time wise than using a thermo probe plugged into a hand meter.

Steve
Santoker Rev 500, Baratza Vario-W, HG-One, Bunn Trifecta MB, AeroPress, Londinium I
 
Barrie
Hazbean, Good to "talk" to you again. This is great information and I can almost foresee what I am going to get from the company - not as much as you are providing.
As for the drying phase elimination, and preheating to 482, that is very interesting and the opposite to what "everyone" else has been saying. However, if you get to yellow in 4:30 that seems about right. I am surprised also that when you drop from 482 to 468 (242C) after 1C it takes you four minutes to get to 2C. Depends on the bean and quantity but the general impression I get is that your setup results in a slower roast than many, including mine. Maybe its all those holes you drilled. Roflmao
I know from my own records that I would get there a lot quicker, but that's what makes a ball game, as the saying goes.
Barrie (San Diego, CA)
"So much to learn, so little time."
Hottop 2K+., Artisan, Jura Capresso ENA 3 (i.e. espresso).
 
Steve Egge
Another temp experiment ... I tried to do this so there was less variability.
In my machine I hit first crack at 460 - 464 readout on the temp ... that Is I think I hear it at 460 .. but not really sure .. notice the start of chaff and buy 464 there is no doubt that first crack is well underway ... so took temp reading 1 minute after hitting 460 (meaning I was still in first crack but not done)

I put on a Kill A Watt on the outlet and my voltage is 120 ... with the Gene on full it pulls it down to 117 and cycles a bit from there to 120 which I think is fairly normal.

227 grams of beans
preheat to 400
dry x 350 x 4 or 5 minutes
482 till 1 minute after reaching 460 degrees - E stop ... shift beans to left side of drum, stand up and insert thermaprobe ...

4 minutes of drying ... hit 460 at 10:30 and got the E stop at 11:45
Bean temp was 388 (first crack started at 10:45 by my ear)
bean wt was 197.7 gm for 12.9% weight loss

5 minutes of drying ... hit 460 at 11:13 and E stop at 12:15
Bean temp was 382
bean wt was 197.4 gm for 13.0% weight loss

Kind of reminded me of chem labs in college ... lots of variables but sure seemed to answer at what temp the beans were at when first crack commensed. I thought the bean temp would be higher on the 5 minute drying .. but it the higher level on the first try might have been due to the extra 15 seconds of time before I could get the drum out.

Just thought I'd share.

Steve
Santoker Rev 500, Baratza Vario-W, HG-One, Bunn Trifecta MB, AeroPress, Londinium I
 
ML
so Steve - you pre-heated your drum to 400*--with 8 oz of beans--did you place the beans in a cold (room temp) drum? then warm the drum to 400* --time elapsed?
or did you pre-heat an empty drum to 400*; elapsed time?, Estop then add the room temp beans?
then 'dry' the beans; better result at 350* for about 5 mins instead of 4 mins
if you added the beans to a cold drum then you dried for x mins @ 400* then continued drying for 5 mins @ 350*
total drying time x+5 mins? too long? sour taste? did you rest the beans for 72 hrs? if not try that

hazbean preheats the drum until max then Estops then adds the beans then roasts at max and yellows at about 4 1/2 mins

my question or observation seems to be that:
The GC dries (yellows) the beans at any temp the drum temp starts at when one adds the beans--- room temp to 482* in about 5 mins
be it inserting the beans at 482* as hazbean and Barrie has observed or 300*-350* as Steve and Ryan and others have found
or inserting the beans at a room temp and setting the temp anywhere from 300* to max (482*) for about 5 mins
that 5 min mark comes up again and again
I'm going to write a song of thanksgiving a hymn of praise a paean to 5 mins
as soon as my GC arrives and I know what it is I'm writing about
 
Barrie

Quote

Steve Egge wrote:

Another temp experiment ... . notice the start of chaff and buy 464 there is no doubt that first crack is well underway ... so took temp reading 1 minute after hitting 460 (meaning I was still in first crack but not done)

Steve


Steve, chaff comes off before first crack, at a time interval that depends on the bean (and perhaps other things).
Barrie (San Diego, CA)
"So much to learn, so little time."
Hottop 2K+., Artisan, Jura Capresso ENA 3 (i.e. espresso).
 
Barrie

Quote

Barrie wrote:

Quote

allenb wrote:

Thanks Barrie, I think I'm finally gaining understanding of the GC with the very detailed responses you and Sean have provided. I also looked over Eddie's how to you linked to.

As you noted, the heating element assembly appears to have been designed to have a natural, paced rate of rise. I'd like to find a photo of the heater internals some day.

Allen


If I come across anything even more detailed I will let you know. Meantime, these are hard to beat for anyone new to or thinking of buying a GC:

http://www.frcndigital.com/coffee/genecafe.html

http://coffeegeek.com/reviews/accessories/genecaferoaster/EddieDove

There is a conflict as to where the authors think the temperature that is displayed is being measured! To me it makes sense that it would be at the air-entry end, but I am looking forward to hearing back from the company.


I just spoke to Tim, at Fresh Beans Inc., the US distributor. The temperature readout is from the sensor at the exit port from the container. It is not an average from the entry and exit sensors. The sensor at the entry side is for safety purposes. If it reaches an excessive heat it shuts off the heater. So, the statement in Eddie Dove's excellent review and break-down description is incorrect.
Tim also says that the heater is either ON or OFF. It has no capability of delivering variable temperatures. When it reaches the set temperature it servos ON and OFF around that endpoint.

I hope this is useful clarification and apologize for any incorrect information I passed along earlier.
Barrie (San Diego, CA)
"So much to learn, so little time."
Hottop 2K+., Artisan, Jura Capresso ENA 3 (i.e. espresso).
 
Steve Egge
ML- On the above tests the beans were added to a hot drum ... preheated to 400 degrees ...probably about 5 minutes.

I always preheat tmy drum to keep the roasts consistent if I am doing multiple batches.

My beans are still green at end of drying phase ...don't yellow up till the heat is put to them usually in my profile at about 7 minutes and then tan at 8:30 ...

Barrie ... yes ... the chaff comes off before I hear the crack. Thought the timing part would take less subjectivity out of it ... but for sure the temps were taken while first crack was going on ... could hear a few snaps as I was stirring the beans.

Steve
Santoker Rev 500, Baratza Vario-W, HG-One, Bunn Trifecta MB, AeroPress, Londinium I
 
ML
Steve, the drying phase ends when the beans are yellow, n'est-ce pas?
so if I understand you
you pre-heat the drum
then you Estop and add the beans
then you set the temp for 350* for 5 mins
then you reset (increase) the temp (on the fly) and the beans yellow at approx 7 mins
the beans yellow at 7 mins?
Is 7 mins too long to reach the yellowing stage?
 
Barrie
Mark,
There is nothing for it but to put some coffee in a cup and taste it. This foreplay can only go on for so long.Grin
Barrie (San Diego, CA)
"So much to learn, so little time."
Hottop 2K+., Artisan, Jura Capresso ENA 3 (i.e. espresso).
 
Steve Egge
ML

for me the whole idea of a drying phase is to get the beans all up temp somewhat gradually before you pour the heat to them.

the idea is not to warm them to yellowness.

IF you are trying for a lighter roast such as city or city plus and if you pour the heat to cold beans then you might get the outside of the bean nice and roasted and not totally permeate to the bean interior as your total roast time is shorter with the lighter roasts. That's why I went to a longer drying period for my lighter roasts and it seems to have solved some tasting characteristics that I associate with under roasting. So it worked for me.

If you like darker roasts like full city plus or Vienna ... then I don't think it is necessary ... YMMV.

Steve
Santoker Rev 500, Baratza Vario-W, HG-One, Bunn Trifecta MB, AeroPress, Londinium I
 
allenb
While it may appear counter intuitive, coffee likes to be pushed hard at the start of a roast and up to the low 200's F bean temp. Once there (1 1/2 to 2 minutes) it's good to back off to a point where there is a smooth curve up through yellow (around 4 1/2 to 5 1/2 minutes) and on to 1C in what ever time meets your fancy. With most commercial fluidbed and drum roasters there isn't typically any hard power changes trying to take the beans in and out of different phases of the roast. The yellow benchmark and 1C are more like passing notes of interest road signs to professional roasters.

If I were to give advice to a new Gene user it would be to experiment with going as hard as possible on start without damaging the surface of the bean and then, (if needed to keep from hitting yellow too early) to back off on the heat somewhat and then find ascending setpoints to get up to 1C in another 4 to 6 minutes.

Obviously, due to various conditions (outlet voltage, ambient temperature, batch size etc) one may not be able to move this rapidly but I would try to get as close as possible to be able to determine if this or the slower curve is to your preference.

Allen
Edited by allenb on 02/18/2013 10:09 PM
1/2 lb and 1 lb drum, Siemens Sirocco fluidbed, presspot, chemex, cajun biggin brewer from the backwoods of Louisiana
 
ML
Allen,
in paragraph one you write about reaching yellow in about five minutes

in paragraph two you write about reaching 1C in about 5 mins

did you mean in paragraph two yellow, I think you did
 
allenb

Quote

ML wrote:

Allen,
in paragraph one you write about reaching yellow in about five minutes

in paragraph two you write about reaching 1C in about 5 mins

did you mean in paragraph two yellow, I think you did


I should have written 'in another 4 to 6 minutes", 4 to 6 minutes after the yellow stage getting to first crack.

Allen
1/2 lb and 1 lb drum, Siemens Sirocco fluidbed, presspot, chemex, cajun biggin brewer from the backwoods of Louisiana
 
ML
Many Thanks, Allen

Steve - I 'm afeared that I ticked you off, earlier -- PLEASE accept my apology

Sorry about all the foreplay Barrie, I promise to get to the climax a whole lot faster in the future
 
allenb
After re-reading I can see how these time/temps are hard to follow. Here's an easier read:

low 200's F -- 1.5 to 2 min
yellow -- 4.5 to 5.5 min (total elapsed time from start of roast)
first crack -- 4 to 6 min (after yellow)

Allen
Edited by allenb on 02/18/2013 10:11 PM
1/2 lb and 1 lb drum, Siemens Sirocco fluidbed, presspot, chemex, cajun biggin brewer from the backwoods of Louisiana
 
Steve Egge

Quote

ML wrote:

Steve - I 'm afeared that I ticked you off, earlier -- PLEASE accept my apology



ML .. no idea what you are talking about ...no offense .. sorry if my reply somehow implied I was ticked ...

I'm still learning on the Gene ... this thread is great with tons of opinions ... What allenb stated in terms of putting the heat on early tugs at my instinct but is worth a try, after all that is what the Gene manual recommends :-) ... interesting stuff going on here ...

Steve
Santoker Rev 500, Baratza Vario-W, HG-One, Bunn Trifecta MB, AeroPress, Londinium I
 
Barrie

Quote

allenb wrote:

After re-reading I can see how these time/temps are hard to follow. Here's an easier read:

low 200's F -- 1.5 to 2 min
yellow -- 4.5 to 5.5 min (total elapsed time from start of roast)
first crack -- 4 to 6 min (after yellow)

Allen

Thanks for your comments, Allen. The only problem is that we have no means of knowing when the beans reach 200. We do have the opportunity to aim for yellow around 5 min and then go for the max to 1C. If by circuitous route, I do think this has been useful, and I am looking forward to making yet another adjustment.
Barrie (San Diego, CA)
"So much to learn, so little time."
Hottop 2K+., Artisan, Jura Capresso ENA 3 (i.e. espresso).
 
hazbean
Hello ML -- rest assured I didn't drill holes in my new roaster, it was well out of the warranty period when I did that!

Barrie -- hello again! What I suggested I don't think results in a slower roast. The objective was to achieve what is a sort of iconic profile in roasting circles -- three phases of approx four minutes each, to yellow, then to 1C, then to the end of the roast. My roast times with that technique were usually in the 12 to 14 minute range, which I'm happy with. The reason for four minutes in the last phase is to get suitable development, a lot of people think that too short a time here means the roast isn't quite as good as it could be (and my experiments supported that view; YMMV of course). The GC will quite happily push through to 2C in less than four minutes, so judgement is important here. Especially as I very rarely roast into 2C, so the point I'm aiming to reach in four minutes is actually somewhat before 2C. Getting it right takes practice.

Of course this isn't the only useful profile. What I suggested is just a technique to achieve the particular 3*4 profile that I found good for many beans (but not all).

Looking forward to the paean to five minutes. Or maybe it will be four ... :)

"Is 7 mins too long to reach the yellowing stage?" A very good question. I decided it was, but I think Steve has some pretty good evidence that it can work. Interesting.

Allen -- I agree with your advice to try the idea of going as hard as possible at the start (the technique I described was informed by similar thoughts). However IME it's necessary to keep the GC going flat out in order to get to 1C in that 4 to 6 minute range -- intermediate set points I found just slowed it down (although such points might be useful for a slower profile). Also I found that the "back off" point needs to be later with the GC than some other roasters (at or a little after 1C on the GC, but on my Quest I'll often back off a good minute before 1C).

Steve -- I see your thoughts are directed towards light roasts, the profile I described is best for roasts that finish say 30 seconds before 2C onwards. Just truncating this profile doesn't work (too grassy). My belief is that light roasts need more development (ie more energy input) before 1C so that the roast can finish not too long after 1C at a suitably light level, but with the total roast time still similar or maybe even longer. In other words, the area under the temp graph up to 1C needs to be greater in order to trade off some after 1C. I never really got it right with the GC, your approach looks promising. However I would make one suggestion -- that you preheat to a higher temp. IMHO this will not harm the beans -- I regularly noted the drum temp on reinserting after my preheat to max, it was usually around 165C/330F. In other words, putting the beans into an ET of around what you want for drying. Note that this starting temp is actually much less than is often used as a drop temp for other roasters.
 
Ryan
Thanks everybody for the contributions to this thread. I believe a higher understanding of the drying phase specifically to the Gene Cafe is already helping improve my roasts. I'm starting to think that tweaking this part of the roast is also helping to mitigate the less desirable qualities of decafs, but I'm still working on that.

ML, having recently gone through the newbie phase with the GC myself, I would recommend just keeping it super simple for your first couple roasts, just to become familiar with operating the roaster. I'd say just skip the pre-heat and go with a simple profile like 300°/5min then 474° till the end of roast for the first time or two. Just my opinion.
 
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