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02/27/2021 9:50 AM
Questions are best asked in the forum. The posts will last longer, and will be seen the most by members. After a few more posts in the Shoutbox, the post you made will no longer be seen.... maybe you could also introduce yourself and share a little.

02/27/2021 9:29 AM
I'm looking to hire someone to teach/help me to find the best roast profile for the 3 types of coffee that grow on my farm in nicaragua. I live in LA, but but could go anywhere in so cal with my Behmor for a roasting lesson. Please contact me if you're in

02/17/2021 7:20 PM
When your wife thinks 30 grams for a 6 cup setting is strong, you learn to drink muddy water when you are making coffee for both of you.

02/17/2021 8:32 AM
I use a rule of thumb of 60 grams per liter. 8 cups (1 liter, 32 oz) = 60 grams, 6 cups (3/4 liter, 24 oz) = 45 grams. 10 cups = 75 grams 12 cups = 90 grams

02/17/2021 1:47 AM
OldMan41, depends what is "a pot"... usually is more accurate to specify the brew ratio, instead grams of coffee. The most usual is 1:15, thus 40 grams for 600 ml of water. If the 100 grams are for one liter pot, then we are talking about 1:10 ratio.

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Scott Rao Shape
ChicagoJohn
Thanks to Nate's post and Allen's follow-up in the "Roasting Coffee" forum, I'm getting lots of new ideas to try. Scott's book is a bit pricy for me just now, but I was able to download excerpts which covered what Nate was discussing. So I decided to try it with a modified air popper and I am posting my results.

You'll see the learning curve between trial 1 and trial 2 -- I think the second one is a closer approximation, but I'll probably average them by blending together before doing a taste comparison against a roast of the same beans that involved a faster straight-line RoR with much shorter time after 1C.

The rationale Scott Rao proposes makes a lot of sense to me and happens to be consistent with the findings of a scientific article I read recently with regard to chemical effects of extending time after 1C.

Allen's comment in the Roasting Coffee forum with regard to the validity of temperature data as generalizable in absolute terms is believable given the many factors influencing such measurements. I think it also reasonable to believe that as long as one is using the same roasting equipment, thermocouple position, etc., relative comparisons are valid and useful, especially when we see repeatability for profiles at similar heat inputs and other parameters for that specific equipment. At least that is my assumption; we'll see how it works. :)
ChicagoJohn attached the following image:
trial-rao-shape-profile.jpg

Edited by JackH on 07/11/2015 12:41 PM
ChicagoJohn
To follow up, I tried the product of this profile this morning and it was hands down the most balanced result I've had from this Uganda Mt. Elgon. I let it cool off for a couple of hours too, and it tasted great cold as well.

As a complete newbie, this is a revelation for me and I plan to try to use this "development" idea that Nate talked about going forward. To aid in setting up target profiles, I decided to do a regression on what I did by eye yesterday using a quadratic model. By changing the a, b, and c coefficients, I will be able to use one of a family of curves to adjust for differences in 1C. But I've found I personally like light roasts because they maintain all of the aromatic fruity, floral elements that Nate talked about. Anything I've tried that even gets into second crack tastes very flat to me; realizing that's just me and others like it.

Anyway, if you're interested, I've posted the model with a graph example, and if you set this up in Excel, you can observed changes in the graph as you try different values for a, b, and c to accommodate specific examples.
ChicagoJohn attached the following image:
quadratic-rao-profile-model.jpg
ChicagoJohn
I tried the same profile I used with the Uganda on Ethiopian Yirgacheffe but I found that 1C was occurring about 10C (18F) lower putting the development time way outside the range Scott Rao suggests. So I decided to compare this batch side-by-side with a second batch that comes closer to the target development time versus total time yet which terminates at the same maximum temperature.

This was the first batch I tried indoors in our kitchen with my wife's permission, using the chaff collector. Not one piece of chaff escaped and clean-up was easy by putting tap water into the collector and then flushing the chaff into a screen sieve before tapping into the trash can.

We did have an aroma in the kitchen that anyone walking in would assume came from making toast for breakfast; nothing that intense or objectionable, but I don't think I would do more than two batches at a time.

Anyway, while the first batch with much longer development time was quite good and very drinkable, the second batch with close to target development time was very noticeably better in terms of a fuller spectrum of aroma and flavor and sweetness.

So for me this experiment definitely supports Rao's recommendation. Thanks again to Nate for talking about development because as a newbie, I'm looking for exactly this kind of guidance.
ChicagoJohn attached the following images:
comparison-of-development-times.jpg yirgacheffe-target-development-time.jpg yirgacheffe-long-development.jpg
BobbyM15
That's interesting. Thanks for posting this.
Coffee is a language in itself.

Jackie Chan
ChicagoJohn
I'm a total newbie to roasting and I'm using a modified popcorn popper. While specific temperatures obtained from one roasting system will likely not apply to another, I thought I'd provide the following which yielded a marked difference in taste, at least to me.

These were 91 gm samples from the same 1 lb Ethiopia Harrar "Deep Blue" from Happy Mug. I was trying to replicate their recommendation in the longer, higher end temperature trial, but I was disappointed with the flatness of taste that seemed to be missing much of the fruitiness Happy Mug described.

So I tried what seems like a small change, reducing the time after 1C and the maximum temperature. What a difference -- to me, being new to this, a surprising difference. The 1 minute and 7C/13F difference resulted in much more fruitiness and a broader range of flavor, if that is how it's described.

Anyway, just thought I'd share these results and I'd appreciate any comments.
ChicagoJohn attached the following image:
harrar-profile-comparison.jpg
spcmn_spiff
I really like the idea of just inputting a few simple parameters into my roasting software and having it follow a setpoint curve and roast to the desired profile. ie.

start temp = 80 F
final temp = 415 F
roast time = 12 min
estimated first crack temp = 385
development ratio = 80%

It is much more intuitive and easier to tweak than a typical ramp/soak profile.
ChicagoJohn

Quote

spcmn_spiff wrote:

I really like the idea of just inputting a few simple parameters into my roasting software and having it follow a setpoint curve and roast to the desired profile. ie.

start temp = 80 F
final temp = 415 F
roast time = 12 min
estimated first crack temp = 385
development ratio = 80%

It is much more intuitive and easier to tweak than a typical ramp/soak profile.


I agree that the idea is appealing in its simplicity. The proof will be in the pudding, of course, or in this case the coffee. forum.homeroasters.org/images/smiley/forumsmiley2696.gif
So many beans; so little time....
Anchorage42
John, what roaster are you using to do this?
BenKeith
I'm not sure what you are using but if it's a small air roaster, I would think getting that same curve is going to be extremely difficult without a PID. The mass of beans is so small, they gain and loose heat too fast. I can break mine up into an number of set points and make it do it, but I have not found where it was worth the effort. I think I use five set points and make sure it hits the white, yellow, toast, FC and EOR, exactly when I want to but the lines between those points tend to be much straighter and just make bends at the set points I change the RoR on, but the time and temp for that set point is dead on. It's still maintaining a steady increase in temp but at a much more exact RoR so the lines are fairly straight between set points.
BenKeith
I looked for a good one but I usually don't save the chart unless I'm working on developing a roast. This is one from back in Feb for a roast I was working one but not a very good one, but does give an idea of how my curvs look.

I don't use any filtering so the lines on the chart have a tendency to be a little jagged. I could filter them and make them all nice and smooth so they looked nice.

I also start the roast with the beans in the roaster and don't drop them at a certain temp. Mine will gain heat fast enough, I quit doing that, to get a more consistent starting point.

The way I have mine setup to control the roast, I can't chart the cool down but it's approx. 2-1/2 minutes to 120F.

i903.photobucket.com/albums/ac239/BenKeith/Columbian%202016-02-19_zpszdli12mm.png
Edited by BenKeith on 10/04/2016 6:41 AM
Anchorage42
Thanks Ben, not to hijack this thread but because you're here and more knowledgable than I....

You're correct, for now I'm in an air popper but thinking about transitioning to a Behmore 1600+ or an SR700 for more control over temperatures and times. What I think I'm coming to find is that by extending the drying stage, what I'm really doing is making sure that the insides of the beans have the opportunity to develop on par with the outside of the beans.

My first 4 or 5 roasts (100g), the outsides got really dark and there was not much left but roast flavor. After that, I've slowed down the drying phase by using a long extension cord and seem to be getting more development. Today, I pulled the plug mid-first crack looking at the color of the beans to determine when. I just brewed up a batch and am thankfully without that char/roast flavor but noticing a brightness that might be grassiness? Maybe I need to speed up the first crack with more heat?

Does this line of thinking actually make sense?
BenKeith
Trust me, I'm no expert on this stuff, just been doing it a long time and still trying to figure it out for myself. I've redone my process several times over the years. I've tried fast roast that would finish in five minutes. Steady RoR @ 25F - 30per minute to FC and then slow it down. Fast roast to FC and then slow it way down etc.

For the past two years I've been using a fast drying phase, bringing the beans up to white (approx. 300F in mine) in four minutes and the slow it down in a couple of steps to reach FC (rolling FC) in nine to ten minutes and finish in two to three, depending on how light or dark. Now, if I am for some reason taking them into SC, all those times are extended slightly. I'm comfortable with a roast that drying to white is 25%, white to rolling FC is 50% and FC to EOR is 25%. This is pretty much where I start and work from there on new beans. Changing times in any of these three as little as fifteen seconds has a very different effect on the roast so I only change one at the time.

Now, until I got into using the TC4 and really learning how to use and set it up, none of what I do now was possible. There was no way in h**l I was going to be able to change any phase of a roast by a given amount of time and do it reliably on back to back roast, that just was not possible with a small batch air roaster. Maybe a high quality, large batch drum roasted but not a cheap piece of junk like I have.

Also understand, I am in no way trying to say you need a TC4 or PID, they are not for everybody and there is a huge learning curve to learn how to get the control I get. It's actually not something I would recommend unless you want to spend a lot of frustrating time learning it. Even then, you can roast for months with everything going great, then the planets or something change alignment and it all goes to h**l in a hand basket.
Edited by BenKeith on 10/04/2016 4:42 PM
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