topbanner.gif
Login
Username

Password




Not a member yet?
Click here to register.

Forgotten your password?
Request a new one here.
Shoutbox
You must login to post a message.

snwcmpr
Offline
· 04/08/2020 7:42 AM
daniboy... You will best get an answer if you post in the forum. And the reply will be available afterwards, also.

daniboy503
Offline
· 04/05/2020 10:37 PM
i need wiring modification for westbend poppery I that has AC fan with rotary dimmer and AC fan speed control switches Thank you!

allenb
OfflineAdmin
· 04/02/2020 4:50 AM
Morning Ed, I haven't done any green coffee hoarding yet but am hoping the supplies don't end up like the toilet paper isles!

snwcmpr
Offline
· 03/31/2020 2:53 PM
Hey Ed. Thanks. roar

homeroaster
Offline
· 03/31/2020 11:21 AM
Hey quarantined home roasters! I hope you have great coffee! If they have a run on coffee, I hope you're set with your great home roast! Find me on Facebook! Ed Needham

Users Online
Guests Online: 6

Members Online: 0

Total Members: 6,479
Newest Member: Megaomgchen
In Memory Of Ginny
Donations

Latest Donations
Anonymous - 5.00
Anonymous - 5.00
renatoa - 2.00
JitterzZ - 2.01
renatoa - 2.00

View Thread

Who is here? 1 guest(s)
 Print Thread
Drying Phase in my Gene Cafe
Ryan
I found that pretty much everybody recommends a 5 minute drying phase at 300° with the Gene Cafe. I'm not trying to refute that in any way, I'm just trying to learn my own GC roaster and put together some generic profiles.

When I try the 5/300 drying phase, my beans are still very much green at this point. In fact, if I keep it going at 300°, I get yellow beans closer to 8:00 in. Is this normal or is the goal to have yellowing at that 5 minute mark? I suspect that my roaster is particularly slow, which wouldn't surprise me given its age.

I pre-heat my drum to 350° before adding the beans. I figured out that if I use a 6 minute 401° drying phase, that is the point where I'll have yellow beans. I can use 5/300 for decaf, at which point I'll have yellowing.

I'm just wondering what other roasters and Gene Cafe owners think about this?
 
Ryan
OK, a more direct question to other Gene Cafe owners... If you preheat your roaster then do a 5 min / 300° dry phase, are your beans still green in color at this point?
 
Steve Egge
YES .. on my roaster I turn the temp up to 464 and hit yellow in 4 minutes from when I crank it up (if I dry for 4 at 300 I hit yellow at 8 and tan at 9.5) ... I don't think 300 degrees is enough to turn the beans yellow ... certainly not at 5 minutes ... Just my experience. I do dry at 300 to try to even all the temps out per roast .. but just do 4 minutes or so ... no problem with 5 minutes ... just want to get on with it ... YMMV ... Steve
Santoker Rev 500, Baratza Vario-W, HG-One, Bunn Trifecta MB, AeroPress, Londinium I
 
Ryan
Interesting, thanks Steve. So, if you dry at 300 for 4 minutes then crank it up to 464, hit yellow around 8 minutes, when do you typically hit 1st crack?
 
Steve Egge
I hit first crack between 12 and 13:30 just about all the time.

Steve
Santoker Rev 500, Baratza Vario-W, HG-One, Bunn Trifecta MB, AeroPress, Londinium I
 
Steve Egge
Just ran an "Experiment" ...
I preheated the Gene for 10 minutes at 350 degrees ...

Stopped and added green beans and started roasting at 300 degrees for 5 minutes...
Stopped roast ... didn't dump beans but placed upright in holder with top open
interted a temp probe into the beans ... it was suspended off the metal grid and held in place, it took a while to come up to temp but highest bean temp reading was 217°F

Bean weight loss was 227 --->221.9 or 2.25% weight loss during this 5 minute drying.

This finding makes me feel comfortable with this drying period ... that is the beans are not stalled and are still absorbing heat ... slowly.

I plan to do a bit more of this but am waiting on a part to help with the testing.

Steve
Santoker Rev 500, Baratza Vario-W, HG-One, Bunn Trifecta MB, AeroPress, Londinium I
 
Bmb
Trying out the Claus Fricke Double Roasting (or two stepped) method.
In a nutshell: the idea is to dry the beans, at 160C for 8:5 minutes in the first step, dropping and cooling the beans down to room temp (10 to 40 minutes). No roasting takes place during this step, only drying. In this step alone I get around a 3,5% weight decrease.
Especially useful with recently harvested beans, that may have a higher water content, which is quite frequent here in Brazil.

The second step is roasting, and here he recommends a 5' warm "loading" phase, and after that doing your usual roast (without the drying phase, of course).

The taste difference, IMHO, with normal roasting, is that it manages to get more "varietal characteristics" (more fruit - flower taste and aroma), in a clear roast.
GC, Bezzera Strega, Macap 4M, Graef ES90, Lido, Mokas, Drip, AP & Co.
 
Barrie
I have yet to be impressed with the usefulness of a drying phase with my setup, environment and beans. I recently gave it another shot. The first run of 227gm SM Moka Kadir taken to Vienna/Vienna+, used my more routine profile, which is preheat/beans in/482 to 1C/440 to end. Next I used Eddie Dove's basic profile which included a drying phase, slow rise, and no decrease after 1C. We drink espresso and my wife's immediate comment after drinking the ED profile was that the coffee tasted "bitter." I felt it had lost much of its maltiness and chocolate taste. Baked beans?
Barrie (San Diego, CA)
"So much to learn, so little time."
Hottop 2K+., Artisan, Jura Capresso ENA 3 (i.e. espresso).
 
Barrie
There is an interesting discussion going on in the Roasting Coffee section regarding the drying phase (IP: 67.166.10.193) and I am now wondering whether much that is handed down from the experts stems from the need to slow down professional level roasters with "super heaters" in the early phases, and this does not translate well to the GC with its less powerful heater and slower early temperature rise.
For example, if I do a control run and put 227 gm beans in the GC with no preheat and the set point at 482, it reaches 400 with amber beans in about 12 minutes, going from pale to yellow to amber during the previous minute. I get to 460 and first crack at about 12 minutes. Has it not gone through a drying phase in the first five minutes? Are the beans likely to be inadequately dried in the center? Exactly what is added by preheating and a targeted drying phase?
Barrie (San Diego, CA)
"So much to learn, so little time."
Hottop 2K+., Artisan, Jura Capresso ENA 3 (i.e. espresso).
 
allenb

Quote

Barrie wrote:

There is an interesting discussion going on in the Roasting Coffee section regarding the drying phase (IP: 67.166.10.193) and I am now wondering whether much that is handed down from the experts stems from the need to slow down professional level roasters with "super heaters" in the early phases, and this does not translate well to the GC with its less powerful heater and slower early temperature rise.
For example, if I do a control run and put 227 gm beans in the GC with no preheat and the set point at 482, it reaches 400 with amber beans in about 12 minutes, going from pale to yellow to amber during the previous minute. I get to 460 and first crack at about 12 minutes. Has it not gone through a drying phase in the first five minutes? Are the beans likely to be inadequately dried in the center? Exactly what is added by preheating and a targeted drying phase?


Most commercial and semi-commercial roasters have at least a small amount of power headroom if not more. Every roaster I've ever built has had quite a bit of headroom but mostly resulting from over-design due to a fear of getting through the build and not being able to get the job done.

Consumer non-convection type drum roasters as with the Hottop seem to be designed with little headroom and convection type (Gene) capable of 1/2 lb batches are necessarily limited in headroom due to the limitations of 120 V household circuits.

If any roaster spends 11 + minutes getting to yellow or even amber assuming it didn't take 9 minutes getting to 250 F it will be very dry and there will be no need for trying to create a drying phase.

I'm curious that some seem to have much more available power with their Gene than others. I've read posts from some Gene users reporting the ability to hit yellow in 6 min or less and others cannot. I wonder why the variations with the same roaster?

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

Quote

Barrie wrote:


For example, if I do a control run and put 227 gm beans in the GC with no preheat and the set point at 482, it reaches 400 with amber beans in about 12 minutes, going from pale to yellow to amber during the previous minute.


I've been rereading previous posts on the Gene trying to see examples of speed to yellow and onward. After reading your post again I've got a question.

Are you saying that with a setpoint of 482 F, at the 12 minute mark your Gene is only sending 400 F into the roast chamber?

If this is the case then there is something wrong with your Gene's ability to heat. Or, is this normal for other GC's?

Allen
1/2 lb and 1 lb drum, Siemens Sirocco fluidbed, presspot, chemex, cajun biggin brewer from the backwoods of Louisiana
 
troposcuba
Allen, I think you would have to play with a GC to fully grasp how it acts. If you set it to 482, it does not jump directly to that temp. The heating element may be running full power, but it is not enough to instantly jump to the setpoint. I think they actually worked it out pretty well in the engineering of the machine to account for the thermal mass of the drum and coffee etc. If you just set it to max and let it run, then cool when it reaches the desired roast, for the most part you will not have scorched beans. I don't think this is the way to acheive the best results from the machine however.

And to answer your question, I think that this is going to be a similar reaction from any GC, but they may reach the set temp at varying times, and I do not think there is anything wrong with the unit in question. it does seem to be the normal mode of operation.
Sean
 
allenb
Thanks Sean,

I guess I'm too used to seeing any convection heater whether it be a tubular or nichrome be able to climb to a setpoint within a few seconds and even with the tubular which is slower to react, no more than a minute or so.

I wonder if the Gene has something else going on control wise other than the cycling relay that allows a gradual rise in discharge temp?

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

Quote

allenb wrote:

Quote

Barrie wrote:


For example, if I do a control run and put 227 gm beans in the GC with no preheat and the set point at 482, it reaches 400 with amber beans in about 12 minutes, going from pale to yellow to amber during the previous minute.


I've been rereading previous posts on the Gene trying to see examples of speed to yellow and onward. After reading your post again I've got a question.

Are you saying that with a setpoint of 482 F, at the 12 minute mark your Gene is only sending 400 F into the roast chamber?

If this is the case then there is something wrong with your Gene's ability to heat. Or, is this normal for other GC's?

Allen


I think you already have an answer, Allen. To better understand the GC, you might be interested in looking at Eddie Dove's instructions as to how to get inside it, complete with photographs and annotations.

https://docs.google.com/presentation/d/1SXVoYgJjz8qSS-2y1-K966At92XK_CYD7UA34JddvUs/edit?pli=1#slide=id.i0

There, you will see that there is a cast metal "Heater/fan assembly" through which the air passes en route to the rotating bean container. In that container, a metal plate and the plexiglass become very hot and the beans are tumbled in hot air as the drum rotates around its excentric axis. The temperature sensor is at the far end of the metal-assembly path and so, during a roast set to max and starting with a cold GC, the assembly has to come up to heat. as well as the beans. That process accounts for the delay. With my machine, if I preheat to 350, stop to drop beans in, and restart with the setpoint at 482, the temp readings are (for example) 1min: 340/2min: 375/3min: 390/4min: 412/5min: 435. This all depends on how long I take to put in the beans with the unit stopped, mass and type of beans, as you might guess. The temperatures are higher than BMT, of course.
The point is that, even with preheat and max setting one is not hitting amber until 3-4 min (I think the heater is either on or off and nothing in between but I am not sure). It might be a good idea to hold at 400, which is amber point, or a little below until 5 min? Trial and error with specific beans is the answer of course, but what is your gut feeling?
Barrie (San Diego, CA)
"So much to learn, so little time."
Hottop 2K+., Artisan, Jura Capresso ENA 3 (i.e. espresso).
 
Barrie
Allen, I misstated the times from a cold start. From the record of one roast I just looked at, 400 at 7 min and 1C/460 at about 12:30. The time to amber is different but the general idea is the same.
Barrie (San Diego, CA)
"So much to learn, so little time."
Hottop 2K+., Artisan, Jura Capresso ENA 3 (i.e. espresso).
 
allenb
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
1/2 lb and 1 lb drum, Siemens Sirocco fluidbed, presspot, chemex, cajun biggin brewer from the backwoods of Louisiana
 
ML
My GC is on its way from SM's and should arrive later this week.
I have figured out how to handle any smoke issues by clearing a large swath of desk space, which sits right in front of the one and only window, and placing the GC right underneath the window. I have purchased 8' of 3" aluminum tubing to vent this bad boy right out the window. Cool Breeze Mahn
I think the question of Barrie's interesting threads is "is there is a real need to warm the GC up prior to inserting the beans into the roaster to roast the coffee to GC perfection (whatever that is)"? Roasting coffee in the GC is not like baking a cake or bread in a pre-heated oven. It's utilizing a home roaster with some unique limitations and roasting coffee beans. Will pre-heating the GC dry the beans quicker and better than not pre-heating? Quicker and better meaning the end result being a better roast. Will beans dry from a cold GC in about the same time as a pre-heated GC? And if it takes a bit longer will it affect the end result? Drying too fast with too high a temp is not logical. Just drying from a cold start seems to make some sense to me but then again I don't know what I'm talking about but it was fun saying so. Are experienced GC users pre-heating just because....., or is there a reason physically and/or chemically happening inside the bean to justify this? Anyway, Barrie posited the question and the consensus seems to lean towards pre-heating the GC. I will try both. Am I having fun, yet? y'bet!
 
Barrie

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.
Edited by Barrie on 02/17/2013 6:14 PM
Barrie (San Diego, CA)
"So much to learn, so little time."
Hottop 2K+., Artisan, Jura Capresso ENA 3 (i.e. espresso).
 
Ryan

Quote

Barrie wrote:

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.


Well, to throw in another possibility, I was under the impression that the temperature readout was actually some sort of average calculation between the two sensors.

ML, I think that preheating the roaster has a few benefits. Having the roaster preheated to a set level every time helps with consistency for one. Also, it seems to help the roasting process get moving along a little more quickly without subjecting the beans to anything that's going to hurt them. That's what I've found at least, maybe more experienced roasters know of other benefits.
 
hazbean
Been away from forums etc for a few weeks, come back to see quite a bit of activity on the Gene front!

I'm not using my Gene a lot at the moment, but I did look into these things a fair bit during the four years or so that I was using it all the time.

Re the temp readout. I'm pretty confident that this number is primarily derived from the left hand (exit ) end sensor. These are my reasons for thinking that:

1. I drilled holes and put a K-type TC probe at the same position. The readings from that tracked almost exactly the GC's probe in the roasting temp range.

2. The GC information repository at coffeetime.wikidot.com reports a similar conclusion see eg http://coffeetime.wikidot.com/inside-a-gene-cafe. This wiki is a very useful resource for GC information.

3. I measured the air temp (as it enters the roast chamber) at the right hand end at 320C.

4. Once I inadvertently roasted 300g of very chaffy beans. Chaff built up on the collector to the point where the wiper couldn't get rid of it and the airflow blocked. The temp readout plummeted, but power didn't -- it was obvious that the BMT was rising, very nearly to the point of ignition. Clearly the temp readout fell because the flow of hot air over the sensor was restricted.

The GC control system (embedded in its PIC microcontroller) uses the right hand (heater) end sensor for error conditions, and also to cycle the heater in certain situations, probably related to the difference between the two sensors. A friend and I have spent ages trying to figure out exactly how this works, but it is not obvious. The answer would be in the PIC code, but the controller has (unsurprisingly) been nobbled to prevent reading the code out.


Re drying cycle and preheating. For a long time I used a specific drying phase, but was often frustrated that it slowed the roast and I couldn't do faster profiles when I wanted to. I concluded that the GC was actually heat limited, and the best way to treat it was to get as much heat as possible into the roasting environment as soon as possible. Consequently, my basic technique is to set it to max (250/482), preheat until max is reached, then add the beans and continue to run at max until around 1C, then drop back to some empirically determined point (usually in the 238 to 242C range) that allows the roast to get to a bit before 2C in about four minutes. I was happy with the results from this, and ended up using it most of the time. This technique sees yellow reached at around 4:30, which is the desired outcome of drying anyway -- so the drying phase is essentially implicit in the profile.
 
Jump to Forum:

Similar Threads

Thread Forum Replies Last Post
Gene Cafe For Sale JAVA TRADING COMPANY 1 02/25/2020 8:09 AM
Profiling with Gene, SR800 and Kaldi wide WHAT SHOULD I BUY OR MAKE 2 02/18/2020 1:38 AM
gene café shut down Gene Cafe Roaster 11 12/10/2019 12:12 AM
Gene Cafe Disappointment Roasting Coffee 8 07/27/2019 2:17 PM
Large Chaff Collector For Gene Cafe Gene Cafe Roaster 1 12/30/2018 2:09 PM
Homeroasters Association Logo, and all Content, Images, and Icons © 2005-2016 Homeroasters Association - Logos are the property of their respective owners.
Powered by PHP-Fusion copyright © 2002 - 2020 by Nick Jones.
Released as free software without warranties under GNU Affero GPL v3.
Designed with by NetriX