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JackH
OfflineAdmin
· 08/10/2020 8:46 PM
Had to make myself another cup of coffee to get through it.

snwcmpr
Offline
· 08/10/2020 7:33 PM
I went into withdrawal for a bit. Now .. all is good. roar

mtbizzle
Offline
· 08/10/2020 7:26 PM
Yeah Jack I think so, I couldn't access for a bit

JackH
OfflineAdmin
· 08/10/2020 6:51 PM
Did we lose the site for a while?

JackH
OfflineAdmin
· 08/06/2020 3:33 PM
Allenb, how are you doing?

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Development to total roast-time ratio
Barrie
There is a discussion on the HB forum related to the importance or otherwise of the ratio of the time from the start of first crack to Drop, to total roast time. It arose because of a recommendation that this ratio is best at 25%, regardless of bean or roaster. No supporting data was provided. This seems highly improbable to me, but I wonder what other HT users think?

Roasting for espresso, I press Eject at 2C + 10 secs most commonly. Time to yellowing is about 5 min., to 1Cs a further 4.5 to 5.5 min, And then a 1Cs to 2Cs interval of 3.5 to 4 min. So, the 1Cs to Eject ratio here is about 4/14 or 29%. I had never thought about this ratio until I read that HB thread.
Barrie (San Diego, CA)
"So much to learn, so little time."
Hottop 2K+., Artisan, Jura Capresso ENA 3 (i.e. espresso).
 
allenb
Hey Barrie, better late than never? I've checked my roasting logs after reading Scott Rao's new book and I'm typically around 15 to 20 %, 1C-finish / total time.

Over the last few days I experimented with his (I hope I don't get clobbered for calling it his) declining rate of rise throughout the so-called browning phase and with a 1C to finish closer to a 25% proportion of total roast time roasting Happy Mugs Uganda Sipi Falls. It wasn't a huge improvement but it was better than what I had been getting and brought out certain favorable notes I had not noticed before with this coffee. If nothing else, I'll be using this profile side by side my usual default trial roast profile for a new coffee of 6-5-2 to help determine best practice for them.

Allen
1/2 lb and 1 lb drum, Siemens Sirocco fluidbed, presspot, chemex, cajun biggin brewer from the backwoods of Louisiana
 
Barrie
I haven't tried any roasts to his prescription yet, but at least with a Hotop it might be difficult to take a roast to FC+ with the recommended 20-25% ratio, while mainsining a constantly declining RoR? My three phases tend to come out to 5-5-3.5, ie 25.9%. Maybe I will try shortening that FCs to DROP interval a bit and see what happens. I must admit that I have been focussing on 5min for load to yellowing, then 4min for FCs to DROP. Scott would at least approve of the shape of my BT curve. Regardless, one effect of reading his book has been to make me look more critically/thoughtfully at what I am doing, and from a more-informed perspective. That has to be good?
Barrie (San Diego, CA)
"So much to learn, so little time."
Hottop 2K+., Artisan, Jura Capresso ENA 3 (i.e. espresso).
 
snwcmpr
Wouldn't that time to finish (ratio) be determined by how dark you want the roast to go?
If not, then that would mean that a French Roast would have the same time to finish as a City Roast.

I roast City or City + ONLY.
4-4.5-1.25/1.5

Ken in NC
--------------
Backwoods Roaster
"I wish I could taste as well as I wish I could roast."

As Abraham Lincoln said "Do not trust everything you read on the internet".
 
allenb

Quote

Barrie wrote:

I haven't tried any roasts to his prescription yet, but at least with a Hotop it might be difficult to take a roast to FC+ with the recommended 20-25% ratio, while mainsining a constantly declining RoR? My three phases tend to come out to 5-5-3.5, ie 25.9%. Maybe I will try shortening that FCs to DROP interval a bit and see what happens. I must admit that I have been focussing on 5min for load to yellowing, then 4min for FCs to DROP. Scott would at least approve of the shape of my BT curve. Regardless, one effect of reading his book has been to make me look more critically/thoughtfully at what I am doing, and from a more-informed perspective. That has to be good?


I'm looking forward to hearing how you come out with your Hottop in trying to get closer to Scott's ideal profile.

I'm going to work on trying to produce a smooth S curve with as few abrupt zigs and zags from over corrections as possible. It looks like its going to take a little more tweaking and rethinking of power application than I thought to produce a smoothly flowing curve especially between 250 and 350F. I'm used to laying on the gas at first to produce a steep ramp at the start and then tapering off hard to not hit 300 too soon then increasing power when approaching 300 to hit my typical 20 to 23 degrees/min during the browning phase. I think one of Scotts aims in all of this is to treat the entire roast more as a whole instead of chapter 1, 2 and 3.

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

Quote

snwcmpr wrote:

Wouldn't that time to finish (ratio) be determined by how dark you want the roast to go?
If not, then that would mean that a French Roast would have the same time to finish as a City Roast.

I roast City or City + ONLY.
4-4.5-1.25/1.5

Ken in NC


Something Scott mentions in his book is this particular ratio is not intended for lighter than city nor darker than city + so I'm not sure how one would tailor the numbers to apply it to those roasts. Might take some experimentation with the ratios.

Allen
1/2 lb and 1 lb drum, Siemens Sirocco fluidbed, presspot, chemex, cajun biggin brewer from the backwoods of Louisiana
 
snwcmpr
Thank you Allen.
That does help. I haven't roasted near to second crack in a very long time.

Ken in NC
--------------
Backwoods Roaster
"I wish I could taste as well as I wish I could roast."

As Abraham Lincoln said "Do not trust everything you read on the internet".
 
Barrie
I have just reviewed a number of past roasts and attached is a very recent one of a bean that I particularly like. The result was an excellent cup of espresso to my taste - good body, taste malty/caramelly, good finish etc. Well-balanced I think for an SO espresso.

Going back to Scott's book, this RoR curve would definitely not be approved, and the "development" to total ratio is 26%, a little high. Of current interest to me is the shape of the curve in the final phase. Sure enough, there is an obvious drop in the RoR during first crack as he describes, and a tendency toward a rapid turn upward after first crack. then a reacceleration. These are artificially-smoothed curves in the graph so the sharpness of the changes is not as obvious as was probably the case.

What I am now wondering is whether to leave a good thing well alone, or play around to see if I can improve it by trying to emulate Scott's recommendation re RoR curve and ratio? Can someone please point me to the page in the book where he says he is only talking about City to City+ or whatever?
[img][/img]
Barrie attached the following image:
capture_6.png

Barrie (San Diego, CA)
"So much to learn, so little time."
Hottop 2K+., Artisan, Jura Capresso ENA 3 (i.e. espresso).
 
farmroast
intro mentions light and medium. Generally from end of first crack city to slightly into 2nd fc/fc+ at edges and beyond in either direction might take slight adjustment considerations

Roasts ended at points during or edge of first crack brings into account more variables such as evenness of the green coffee being used and even specific roaster type heat transfer and control. Somewhat the same at dark roast levels
Ed B.
DreamRoast 1kg roaster, Levers, Hand Mills http://coffee-roasting.blogspot.com/
 
turtle
I've found I don't have that much control using the KN-8828B-2

Seems to not have enough power to move to dry then from dry to first crack where I try to stretch by using fan and burner down.

Everything before that is just wide open and waiting for the time to roll by.

Not a bad product but the limiting factor is the burner power is just a tad too under powered.

Would be nice if they offered a full 20 amp 110v model with more burner. OR a modification that can be made to existing in service roasters.

I get good tasting roasts but I know it can be better
Mick - "Drinking in life one cup at a time"
"I'd rather be roasting coffee"

Roaster 1: San Franciscan SF-1
Roaster 2: Hottop B-2K+
Roaster 3: Behmor 1600 +
Grinders: Modified Super Jolly - Forte BG (x3)
Pour over: Hario - Bee House - Chemex - Kalita - Bodum
Drip: Bunn CWTF15-1 & CW15-TC (commercials)
Espresso: Pasquini Livia 90 auto
Vacuum: Cona - Bodum
Press: Frieling - Bodum Colombia
 
Barrie

Quote

turtle wrote:

I've found I don't have that much control using the KN-8828B-2

Seems to not have enough power to move to dry then from dry to first crack where I try to stretch by using fan and burner down.

Everything before that is just wide open and waiting for the time to roll by.

Not a bad product but the limiting factor is the burner power is just a tad too under powered.

Would be nice if they offered a full 20 amp 110v model with more burner. OR a modification that can be made to existing in service roasters.

I get good tasting roasts but I know it can be better

I have got around that to some extent by using a Variac (and Kill-a-Watt) and turning up the watts a tad. There is quite a bit of discussion around concerning the safety of doing that, in terms of the element and what it will tolerate. Many members of this and other forums have reported on doing multiple back-to-back roasts with no problem, and some regularly crank up their in-line variac to use larger-than-usual batch sizes. It is clearly a roster-beware situation but it does seem that one can venture beyond the manual, if the warranty is not a concern?
My current preferred batch size is 283g, two of which yield just a little over a pound of roasted beans, all depending on the usual suspects. The wattage during the first half of each roast is about 755. I am now thinking of increasing this at the start, to permit a profile more like that described in the book.

As an erstwhile editor of scientific papers, the thing that causes me to hesitate is that, while Scott describes how it turned out that flat-tasting coffee producers had profiles with a bumpy ride (my terminology), he did not describe a "control group" of "perfect cup" producers whose profiles were always smooth. Now that would be persuasive!
Edited by Barrie on 08/23/2014 5:23 PM
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:
As an erstwhile editor of scientific papers, the thing that causes me to hesitate is that, while Scott describes how it turned out that flat-tasting coffee producers had profiles with a bumpy ride (my terminology), he did not describe a "control group" of "perfect cup" producers whose profiles were always smooth. Now that would be persuasive!


Woops. I went back and, sure enough, what Scott does is to review the profiles of some top notch coffee and found they all conformed to his prescription, then he examined the profiles of some "flat-tasting coffee" and found they did not conform. Not a controlled study, but better anecdotal information than I had recalled, and persuasive enough to encourage further exploration. Back to the drawing board/Hottop.
Barrie (San Diego, CA)
"So much to learn, so little time."
Hottop 2K+., Artisan, Jura Capresso ENA 3 (i.e. espresso).
 
JackH
After reading this I looked back at my roast logs going back to 2012 and see that my total roast times are usually about 12- 13 minutes for a 600g load. First crack is at about 9 minutes and end time is at 12 minutes.

So it looks like a 25% ratio from 1C to end for almost all my roasts. I do like the results.

A heat reduction before 1C and smaller reductions after are necessary for me to keep control of the roast and allow me to stretch it out toward the end.

All my logs show a gradual reduction in RoR after 1C to the end.

Ignore the second crack marker in the photo, I usually do not run to 2C.
JackH attached the following image:
guathuehue07072014.png

Edited by JackH on 08/24/2014 5:41 AM
---Jack

KKTO Roaster.
 
Barrie
Very interesting, Jack. I forget what roaster you use, but I imagine it is gas-fired? That creates a much more easily adjustable heat throughout the roast. This as opposed to electric-element heated roasters like the Hottop, in which the heat moves like a tanker changing course at sea - slowly. It does have the advantage of a perforated drum and the element a little away from it, so that the air-flow from the fan becomes an important tool that produces more immediate results even if they are less potent. All this provided one keeps the pathways and the fan itself clean and functioning optimally.
Interesting hobby? Great toys,with lots of information and things to tweek. rockon
Barrie (San Diego, CA)
"So much to learn, so little time."
Hottop 2K+., Artisan, Jura Capresso ENA 3 (i.e. espresso).
 
JackH
Hi Barrie,

It is a KKTO design - electric and uses a 1200W turbo oven top (solid heater element with a fan). I control the heater with a variac.

I guess I got used to knowing when to reduce based on the repeatability of my probe readings and knowing the lag of my heater. The result of many roasts.
Edited by JackH on 08/25/2014 5:02 AM
---Jack

KKTO Roaster.
 
Barrie
Just completed two back-to-back 283g batches of HM India Shevaroy Superior in the Variac-boosted Hottop and had no problem producing a steady decline in BT RoR. So that will not be a problem. Keeping the 'Rao ratio' at 25% or below will be a different matter. These roasts, taken to FC+, are at 26-29%. The next step will be to see whether a smoother decline in RoR has provided any improvement in the cup. I still have not found Scott's statement that his 25% goal only applies to City to City+ roast.
Barrie (San Diego, CA)
"So much to learn, so little time."
Hottop 2K+., Artisan, Jura Capresso ENA 3 (i.e. espresso).
 
allenb
Barrie, I could have sworn that I saw a post in one of the HB threads that quoted a statement by him from the book saying that he didn't expect the ratio and descending RoR to apply to roasts lighter than city nor darker than C+ but I haven't been able to find it either. As farmroast posted , he does imply it in the introduction page:
"For our purposes I will focus on a light to medium roasting of specialty coffee"

I also thought that I'd seen him state it in chapter 8 but I'm not seeing it now either. I might have been dreamin.

Allen
1/2 lb and 1 lb drum, Siemens Sirocco fluidbed, presspot, chemex, cajun biggin brewer from the backwoods of Louisiana
 
Barrie
Allen, thanks for keeping in touch with this issue. The book has been a useful attention-catcher for me as I had fallen into a roasting routine in the quite unjustified belief that it was about "as good as I could get it." Now, there are for-me new aspects to be explored. For example Scott claims that, unless one is planning to use espresso with added milk, the degree of roast that would be pleasing for filter or other brewing methods, would also be preferable for straight espresso, or words to that effect. With my equipment, ending the roast about three minutes or less after FCs, and before SCs would get the ratio down below 25%, and I would have met all three of Scott's commandments. I still harbor the thought that his formula surely can't be universally applicable, but if all it leads me to do is try a lighter roast for espresso, then that will have been an interesting experience. Until very recently I could not have imagined trying a City+ in an espresso machine. Ugh! :-)
Barrie (San Diego, CA)
"So much to learn, so little time."
Hottop 2K+., Artisan, Jura Capresso ENA 3 (i.e. espresso).
 
MikeW
I knew Allen was right, so I had to go find it. Rao makes the qualifying statement in his post on dailycoffeenews.

http://dailycoffeenews.com/2014/08/12...sful-roast

Barrie I hope you are successful in trying out City Plus roasts. I think S.O.s can be fantastic at City+ even with espresso brewing.
 
Barrie

Quote

MikeW wrote:

I knew Allen was right, so I had to go find it. Rao makes the qualifying statement in his post on dailycoffeenews.

http://dailycoffeenews.com/2014/08/12...sful-roast

Barrie I hope you are successful in trying out City Plus roasts. I think S.O.s can be fantastic at City+ even with espresso brewing.

Good morning, neighbor.

>>>To be fair, I don’t often cup roasts dropped well before the end of first crack or well after the onset of second crack, so I won’t assume the ratio is valid for those roast levels.<<<

This is the quote from Daily Coffee News and that whole article reads so much like a page straight out of the book that I went back there to find it, but still could not. From this quote it does sound as though his ratio is intended to include FC and possibly even FC+?
I will report back re espresso from City + roasts but it may be a while. beach
Barrie (San Diego, CA)
"So much to learn, so little time."
Hottop 2K+., Artisan, Jura Capresso ENA 3 (i.e. espresso).
 
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