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03/25/2024 12:38 PM
coffee drink, Ramper?

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BLENDING COFFEE FOR ROASTING
ChicagoJohn
I looked through the various topics and could not find one that was ideal for this concept. If I missed it, it wouldn't be the first time :) Just let me know where.

But anyway, as a total newbie to coffee roasting, I've had some roasts I thought about throwing in the trash can. Some were too light -- too much acid, too much "crack" in compressive strength in my little hand crank grinder -- too light. And some others were too "well done"; very charcoal-like and easy to crush when grinding in my hand crank grinder; morphology of the bean structure mortified. These were never "burned" in flavor but they were very "flat". I can't remember anymore what the "Eight O'clock" beans I was grinding and brewing before in my Mr. Coffee even tasted like, but I think it may have been like this....

But my point is that sometimes I don't throw away the extremes; I just decide to drink them. And sometimes I take one Aeropress scoop of A and one of B and grind them together. There have been a number of these occasions upon which the result has been "my perfect cup".

So my question to those who unlike me have been doing this for years, not weeks, is whether there is a theory or strategy to making a blend. Someone like Tim Wendelboe may say, "we don't believe in blending beans any more than one would blend wines". Yet people do blend wines, and I, in my na?ve state regarding coffee, am only interested in the best taste experience I can have in the morning, not particularly discerning the nuances of this or that single origin; not that there's anything wrong with that.

One would hope that "coffee" presents a very broad spectrum of interests.

Anyway, my question goes to the theory, art, strategies of blending; for those who may be interested in blending. What I am seeming to discover is that if I have a too-dark and a too-light, using one scoop of each in my hand mill for the Aeropress can often make a kick-ass cup of coffee.

So where do I put this question in the various forums? Or maybe it's not really a viable question?
Edited by ginny on 08/08/2015 5:02 PM
So many beans; so little time....
 
oldgearhead
Oh I like to blend in the roaster. About 50-50 with maybe a Kenya AA and
a Mexican. In other words a slower developing with a faster developing to
arrive at a nice cup from beans at different roast levels...However, I must rely on time, sight, and convection air temperature to accomplish this, not bean mass temperature. In fact I haven't used BMT for a long time, and I really don't understand some roaster's blind reliance on it, especially in a fluid-bed roaster..
No oil on my beans...
 
ChicagoJohn

Quote

oldgearhead wrote:

Oh I like to blend in the roaster. About 50-50 with maybe a Kenya AA and
a Mexican. In other words a slower developing with a faster developing to
arrive at a nice cup from beans at different roast levels...However, I must rely on time, sight, and convection air temperature to accomplish this, not bean mass temperature. In fact I haven't used BMT for a long time, and I really don't understand some roaster's blind reliance on it, especially in a fluid-bed roaster..


To summarize my understand of this, and please correct me if I'm wrong, some develop faster than others, so if you blend these and roast them at the same time, you wind up with a mixed degree of development; i.e., one will develop further (the one that develops faster) and one less (the slower one) even though they are roasted the same?

I happen to have some Mexico Oaxaca (although I heard they had a rust hit their trees and will be out of commission for a long time) and some Kenya Kigutha which I think is AA. I know that they often extended the roast for the Mexico to get come chocolate flavor and they recommend a very light roast for the Kenya. So I can maybe give this a try two ways: If I understand this correctly, if I make a mixture and do a medium roast, the Kenya will be more developed and the Mexico less? Then I could also try roasting them separately as recommended (Lt for Kenya, Dk for Mexico) and blend after roasting. These would be sort of opposites, if I'm correctly understanding what you're saying. Your other point is that in a fluidized bed environment, time and air temperature are better indices than bean mass temperature (which would be more difficult to know in this environment, I think, since the beans are more or less separated in hot air).

Thanks for the input, please correct any misunderstandings, and I'll give it a try!
So many beans; so little time....
 
oldgearhead
I think you've got it! Kenneth Davids' book 'Home Coffee Roasting' touches on this in a couple of chapters. Bye the way this excellent 1996/2003 book can still be found at a very low price point and in several libraries.
My comment about bean mass temperature is based on a simple observation; Beans in my electric, one-pound, fluid-bed roaster seem to react more quickly to changes in air flow than changes in wattage. For me, PID is a total waste of time.. I set the air temperature before roasting and adjust the 'development' with the blower speed...The internal bean temperature is inversely proportional to the blower speed...Of course this is because with the wattage constant, the air gets hotter as it slows down...
No oil on my beans...
 
ChicagoJohn

Quote

oldgearhead wrote:

I think you've got it! Kenneth Davids' book 'Home Coffee Roasting' touches on this in a couple of chapters. Bye the way this excellent 1996/2003 book can still be found at a very low price point and in several libraries.
My comment about bean mass temperature is based on a simple observation; Beans in my electric, one-pound, fluid-bed roaster seem to react more quickly to changes in air flow than changes in wattage. For me, PID is a total waste of time.. I set the air temperature before roasting and adjust the 'development' with the blower speed...The internal bean temperature is inversely proportional to the blower speed...Of course this is because with the wattage constant, the air gets hotter as it slows down...


Thanks, oldgearhead. I've been doing a lot of reading on this subject of approaches to blending from many sources on the internets, and your approach is squarely among them. The operative criterion, which makes complete sense to me, is that the result of the blend is preferable to that of the individual elements that are blended. "Preferable" is, of course, a matter of highly individual subjective judgment. Your approach, along with roasting separately to different degrees of development prior to blending, along with the virtually unlimited set of potential combinations of types and levels within that, should keep me busy for a long time; probably longer than I have left :)

While I am using a simple, modified air popper that does not have a fully fluidized bed action, I do think that with the mods I have, the tendency is toward the dominance of convection heating, and since my little apparatus has the capability to make beans move quite well green, and definitely more-so as they decrease in density, I too have noticed the similar effects of increasing power to heating and decreasing airflow. For me, though, it's six versus half-a-dozen, but I can imagine a theoretical basis in a true fluidized bed where closer average bean proximity with reduced airflow could affect rates of heat absorption at constant air temperature, perhaps even accelerating it, counter-intuitively, via potential increases in conduction and radiant heating. Someday maybe I would like to have a fluidized bed system, but I'm so far up the learning curve at this point, 91 gm at a time works much better for me :)

Thanks for your replies!
So many beans; so little time....
 
ChicagoJohn

Quote

oldgearhead wrote:

I set the air temperature before roasting and adjust the 'development' with the blower speed...The internal bean temperature is inversely proportional to the blower speed...Of course this is because with the wattage constant, the air gets hotter as it slows down...


Hi Oldgearhead,
I just finished four roasts with my latest popcorn popper mod, and I kept thinking about your comments. In my set-up, I need maximum air velocity initially to keep the beans in motion. But as they approach 1C, their decrease in density allows me considerable latitude in adjusting air velocity.

So after getting close to 1C, I tried your method and left coil power constant and I found that by tweaking voltage to the blower motor I was able to obtain much better results with respect to targeted temperatures than I have been getting with tweaks to heating coils. Perhaps part of the reason is that during 1C the exothermic contribution to heating is easier to control with air velocity than with heating coil power.

Initially I was going to leave the blower motor control out and just let it run at maximum all the time. Now I'm glad I included it. Thanks for your post relating your experience. It has proved to be a big help to me even though my system differs significantly from yours.
So many beans; so little time....
 
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