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Regarding the pre-yellow stage
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| endlesscycles |
Posted on 07/04/2010 11:11
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1/2 Pounder
Posts: 239
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Everyone's roaster is different, but this is where I ask if you don't have power to get to 300F in 3min, do you actually have control of your roaster? If your thermocouple ever reads a drop during the roast, do you really have any clue what's going on? I think these two questions lead one to determine why some roasters have only their senses to assume they have an affect on the roast.
I long since gave up on subjective judgments to guide roasts. The cup is the final word and precise measurement and repeatability guarantee consistency. There's still craft, even more so I believe in being able to truly affect subtle details in the cup.
Power, precision and control. If your roaster is a Buick drum or a moped consumer product: good luck steering a tight profile with steep grades.
-Marshall Hance
Asheville, NC |
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| John Despres |
Posted on 07/04/2010 18:23
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Super Admin
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I find if I scream to yellow, particularly with Ethiopia IMV, I miss the huge fruit and blueberry. It seems to me the fruit is lost, somehow. Hitting yellow at about 6 minutes, 1st at about 11 minutes gives me an outstanding cup.
John
Fade to black coffee
John Despres
Fresh Roast 8, Gene Cafe, JYTT 1k, Mazzer Mini, Technivorm, various size presses and much more. |
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| endlesscycles |
Posted on 07/04/2010 18:52
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Posts: 239
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John,
I agree entirely with your observation.
I think each coffee likely has a best time, rather than standard time to yellow. I don't think it's 100% about moisture, but more in general getting the bean ready for action. One thing that strikes me is that fructose caramelizes early, and maybe it's worth hanging out just above 230F to let those reactions develop on their own before moving on. Putting to light the observation of a DP Ethiopia makes me wonder if we are tying up the fructose into bulkier molecules before degrading them with more heat...that is the intense fruit-sweet sugar.
Good call!
-Marshall Hance
Asheville, NC |
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| John Despres |
Posted on 07/04/2010 20:32
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On the other hand, a faster ramp for a pacamara seems to be a better roast. Ah, the joys of studying the bean!
Guats also seem to love big heat from the beginning. At least my buds tell me anyway.
Fade to black coffee
John Despres
Fresh Roast 8, Gene Cafe, JYTT 1k, Mazzer Mini, Technivorm, various size presses and much more. |
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| allenb |
Posted on 07/08/2010 19:23
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Posts: 293
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I put a couple of roasts through the Sirocco fluid bed last weekend with the 3 min to 300 versus my usual 5 min. One Guat and one Java.
Ramps as follows:
200 F 1 min
200-260 1 min
260-300 1 min
300-335 1 min
335-405 4 min (1C)
405- finish (437) 3 min/10 sec
The Guat was outstanding. Much improved complexity and brightness over the slower starts. What I was not expecting was improved body but it was much heftier as well. Go figure.
I didn't expect the Indo to fair better with the faster start but it was much improved as well although not as much as the Guat. The improvement came in that the woody/earthy tones were much more balanced with an increased nutty and chocolate.
I'm looking forward to seeing how my other coffees do with the faster start.
1/2 lb and 1 lb drum, Siemens Sirocco fluidbed, presspot, chemex, cajun biggin brewer from the backwoods of Louisiana |
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| endlesscycles |
Posted on 07/09/2010 14:11
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Posts: 239
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I have read that speedy ramps increase final bean size and by some function based on that fact, increase body in the cup. As to where to put that speedy ramp, I don't exactly know....but its not happening between 370 and 400, IMO, however that may be a dogmatic assumption.
FWIW: I've stopped speeding then stalling at 280, and am instead taking more of an asymptote shaped profile that comes to a creep info 290's before cranking things back up. I'm finding the smoother heat changes are resulting in a smoother integration of flavors in the cup. Aiming for 300F at 3:30 mostly now.
-Marshall Hance
Asheville, NC |
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| allenb |
Posted on 07/12/2010 13:21
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endlesscycles wrote:
I have read that speedy ramps increase final bean size and by some function based on that fact, increase body in the cup. As to where to put that speedy ramp, I don't exactly know....but its not happening between 370 and 400, IMO, however that may be a dogmatic assumption.
FWIW: I've stopped speeding then stalling at 280, and am instead taking more of an asymptote shaped profile that comes to a creep info 290's before cranking things back up. I'm finding the smoother heat changes are resulting in a smoother integration of flavors in the cup. Aiming for 300F at 3:30 mostly now.
I'd like to know more about the speedy ramp/body increase. Would be fun to experiment with. I and I'm sure a few of us have had issues with a coffee coming out thin but otherwise having great qualities.
In researching the bubblebed I read quite a bit about how the quick roasts "puff up" the beans allowing increased solubility and lower density. Unfortunately, the flash roasting they were using to do the puffing caused a pretty lousy cup. Maybe there's a spot in the profile where you could give it a kick for a short period to improve body.
On another note. Due to less than acceptable bean lift on my fluid bed I had to reconfigure it by pulling all parts except the fan and reassemble into a custom enclosure. The custom setup has a larger blower but otherwise operates the same.
Because of the low cfm I was having to run my ET up to 530 F at certain points in the profile. With sufficient air flow now my ET is never over 480 F. Cup quality with the reduced ET has improved dramatically. Flavor notes much more focused.
With this improvement coupled with using the faster ambient to 300 degrees I'm starting to really like fluid bed roasting. And since I'm naturally impatient it's nice not having to warm it up before the first roast.
Allen
1/2 lb and 1 lb drum, Siemens Sirocco fluidbed, presspot, chemex, cajun biggin brewer from the backwoods of Louisiana |
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| seedlings |
Posted on 07/13/2010 03:01
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I'd like to read about speedy ramps. Any links?
CHAD
"You know, I think that horse is getting deader." |
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| bvwelch |
Posted on 07/13/2010 05:32
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1 1/2 Pounder
Posts: 892
Joined: 27.12.07
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Jim Schulman writes a lot about light roasts and ultra-lights and uses what I'd call speedy ramps. I've got several bookmarks linked, here are a few
http://www.home-b...ml#p111964
http://www.home-b...11876.html
http://www.home-b...11637.html
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| freshbeans |
Posted on 07/14/2010 08:08
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It seems that if you really speed things up, you can produce what I can only describe as pop-coffee. Similar to pop-corn but...you get the idea.
This was a 5 lb load,..6 min to city. it produced about 3 of these pops.
Has anyone seen this before? Scott
freshbeans attached the following image:
[52.03Kb]
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| Unta |
Posted on 07/14/2010 10:22
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Never seen it and I've taken beans from green to on fire in under two minutes and quite often can get in city range in 6minutes or so.I guess the only burning question is HOW'S IT TASTE?that and what beans are they?
Sean
Sean Harrington
educate. |
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| freshbeans |
Posted on 07/14/2010 10:42
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That was a Honduran SHB. It's happened before, but only on the really hard beans.
It was a test load. Ran it very fast as a means to make a comparison to other profiles. As suspected, it was too snappy, and a bit grassy.,
If it were say...Sumatran, I think it would have been very
different. -Scott |
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| endlesscycles |
Posted on 07/14/2010 14:42
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Posts: 239
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I've seen those for sure. I can't remember the exact profile, but I do know that some speedy ramp was involved somewhere; most likely trying to reach 370 in a hurry.
-Marshall Hance
Asheville, NC |
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| seedlings |
Posted on 07/15/2010 13:51
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I recommend: Butter and salt.
Doesn't Sivetz roast hundreds of pounds of coffee in 4 minutes?
CHAD
"You know, I think that horse is getting deader." |
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| freshbeans |
Posted on 07/15/2010 14:27
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Posts: 253
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You're correct. I'm certain Sivetz has alot more CFM, with an overall lower roasting temp.
I've got a smaller, high velocity inlet port and likely a much higher inlet temp. If some poor bean doesn't circulate the way it should....POW .
A bubble bed would likely never produce these ??
-Scott
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| ginny |
Posted on 07/15/2010 14:59
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Posts: 1528
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Doesn't Sivetz roast hundreds of pounds of coffee in 4 minutes?
really?
wow, seems amazing!!
ginny
Keeper of Xanadu, the last bohemian outpost!! |
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| endlesscycles |
Posted on 07/15/2010 19:14
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Posts: 239
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seedlings wrote:
Doesn't Sivetz roast hundreds of pounds of coffee in 4 minutes?
CHAD
If grassy burnt inarticulate beans are considered coffee....
I would say 8 is the least time possible to get an okay cup. I don't care what kind of convection you've got, a bean is more than it's surface.
-Marshall Hance
Asheville, NC |
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| endlesscycles |
Posted on 07/15/2010 19:27
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Posts: 239
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Here's my conclusion on the pre yellow stage;
You reach 50% of your final bean surface temperature increase by between 250F and 270F. Aside from the caramelization of fructose at 235F, most reactions start at 310F. With fructose in mind, you'll want no stalling while warming things up. The more time you spend close but under 310F, the more even the inside of the bean temperature is to the measured value. Lengthy warm-ups will prevent grassy flavors, but extended time will flatten the cup due to sucrose degradation beginning at 194F.
My recommendation is an asymptote shaped ramp to 300F, then progress with the roast according to taste. Time to 300F is relative to the final degree of roast as well as the flavor characteristics of the bean.
-Marshall Hance
Asheville, NC |
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| freshbeans |
Posted on 07/16/2010 06:19
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Agreed, I don't believe you can roast a 4 min load and get anything tasty. I think the curiosity was that they don't pop at that speed. -Scott
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| Unta |
Posted on 07/16/2010 14:52
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Posts: 224
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Marshall,
again, thanks for all the data, much obliged.
sean
Sean Harrington
educate. |
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| John Despres |
Posted on 07/17/2010 11:06
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Posts: 1390
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Marshall,
I'm wondering how you're seeing your asymptote shaped ramp. Since an asymptote ramp would be a straight line with even the x axis and the y axis being asymptote, are you looking for a 45 degree angle climb, more gentle with a slower rise or a steeper rise?
Do you have a graph you can post or can you make a drawing? I'm a little confused and stumped...
Thanks! I'm thoroughly digging this thread, as yellow is my first indicator of roast progress since I cannot measure bean temp in my Gene Cafe.
John
Fade to black coffee
John Despres
Fresh Roast 8, Gene Cafe, JYTT 1k, Mazzer Mini, Technivorm, various size presses and much more. |
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| SteveN |
Posted on 07/17/2010 18:49
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Posts: 33
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my assumption was that the asymptote was parallel to the x-axis at 300 degrees.... now I'm confused! |
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| endlesscycles |
Posted on 07/18/2010 17:15
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Posts: 239
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Fast from room temp to two fifty slowing to a creep around two eighty. I actually like to pass through three hundred at speed.
-Marshall Hance
Asheville, NC |
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| endlesscycles |
Posted on 07/18/2010 17:18
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Posts: 239
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Which means I ramp it back up again aiming for three hundred at a planned time.
-Marshall Hance
Asheville, NC |
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| somegeek |
Posted on 08/03/2010 21:43
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Posts: 37
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John Despres wrote:
Thanks! I'm thoroughly digging this thread...
Lotta good info in this thread regarding the science of the roast - thanks for this!
somegeek (newbie roaster) |
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thanks for your patience and support!
