Advice on Crash & Flick with Electric Roaster

Discuss roast levels and profiles for espresso, equipment for roasting coffee.
cjhacker23

#1: Post by cjhacker23 »

Hello Fellow Roasters,

I now have about two dozen roasts under my belt with the Quest M6 and am still struggling to achieve a "perfect" declining RoR with this roaster. I have been using a 20# bag of Nicaraguan Caturra greens from SM to learn on. The tasting notes suggest City+ (which is my preferred roast level) so I have been dropping between 425 and 435. In order to do this and at the same time keep DTR under 25%, I am targeting dry at 6:00, which gets me in the neighborhood of 430 in around 12 to 13 minutes. FC is by ear, once I hear 3 distinct pops in a row, which comes on my probe at around 392. Charge weight is 400 grams and charge temp is 350. I crank to max power (1500 watts) at charge and start with fan at lowest (3). Just intuitively lowering power and raising fan gradually throughout the roast. This methodology is based on a hodge-podge of stuff I've read, but really just nervous fiddling while looking at RoR curve as it's unfolding.

Analyzing my curves after the fact on Roastmaster, it seems I have a classic "crash and flick" problem. In the heat of the moment (so to speak), I couldn't really identify the problem, so I think I may have been exacerbating the crash by cutting power in the neighborhood of first crack.

Any thoughts on how to mitigate this with an electric roaster such as mine? I know Rao suggests not cutting gas within 45 seconds of FC, and at the same time not "cheating" by raising gas either. But I think that advice is based on heavy gas drum roasters. What about a smaller electric roaster like the Quest M6? Does anyone have thoughts on how to mitigate the crash and flick? Here are 3 representative curves from this weekend:




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CarefreeBuzzBuzz

#2: Post by CarefreeBuzzBuzz »

I think these roasts may not be as bad as you believe. I don't know how hard it would be for you to try using Artisan and run the analyzer feature. I am not sure if you are software can export in a format that Artisan can import. Either way you should be chasing the taste of the coffee and not the perfect curve.
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bean2friends

#3: Post by bean2friends »

I agree. Those roasts don't look too bad to me. I especially like the first one that ended at 425. In any case. I'm betting these taste pretty good. Be sure to let us know.

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TomC
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#4: Post by TomC »

Don't judge your coffee by it's roast curve or what Rao tells you is good. So far, for the most part what I see you doing is a good way to learn, sticking to one coffee, and nailing it. But your successes lay in the cup, not on the screen.

For an electric roaster like the M6,and the the coffee you're using I'd only suggest increasing your charge temp from 350 to 360-365. More momentum early on is important for these electric roasters, and a high altitude washed coffee can easily tolerate such an environment on the outset.

The crash is harder to control, and in my opinion, not as worrisome in the final outcome in the cup. The flick, is IMO a bit more of a problem and should be minimized. Both phenomena are a simple result of what the probe sees when first crack begins and ends. This is an important distinction. I don't really care what happens to the probe, I care more about what's happening to my coffee.

I'd give more detailed advice, but without knowing how your coffee tastes and with detailed notes of the various previous attempts, any specific advice is somewhat worthless.
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Brewzologist
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#5: Post by Brewzologist »

Agree with others those aren't horrible curves. I think Rao's comments you posted also apply to the Quest, but maybe not on the exact times he lists. The challenge with some electric roasters is there can be more delay after a power change where the temperature responds than gas. So you have to plan ahead more where you want your temp to go next. First off, keep the environment you roast in as consistent as you can so it doesn't change much roast-to-roast. Then start making slight changes to when you make a change in power from one roast to another; maybe making a change 10 sec sooner/later than the last roast. This is where using software like Artisan can be invaluable; you can log events (gas/air changes) in your roast, and then use that roast as a background for the next roast to know when to make change improvements.

Specifically to your roast curves, it looks like you are cutting power a bit too quickly perhaps after first crack starts. Try extending the power change through first crack 5-10 seconds before you decline to the next lower setting. To avoid the flick at the end, you have to cut power sooner. There is a lot that happens in that last minute or so to accomplish this, and I can imagine it could be hard to manage if there is a substantial delay in power changes being seen inside the drum.

Another comment; it appears from those profiles that first crack is starting around 396F and you are dropping the roast +30F later? IMO, that's definitely into the med/dark territory. Not sure what your roast preference is, but part of the challenge you may be having is that you are starting to move toward second crack where it can be even more challenging to manage the flick. If you're open to experimenting with lighter roasts more around <+20F after first crack, you might find the flick much easier to manage. Of course that only helps if you like the lighter roast. 8)

As for fan, I suggest finding one setting during a roast and leaving it there, which the roast curves appear to show you are doing? Here's an easy way to calibrate your fan setting: Lighter Trick

EDIT: Just saw Tom's post about the same time as mine. Agree that taste is king more than beautiful curves. But I do personally believe reducing crash to also be generally important to better taste in most roasts.

cjhacker23 (original poster)

#6: Post by cjhacker23 (original poster) »

Thank you all for the replies! I do understand that the proof is in the cup. I have not yet bothered to cup my roasts. Now, before you all admonish me for this, hear out my reasoning (and feel free to disagree!):

I am, thus far, unable to **control** my roaster. This is my first step. I would like to make my roaster do what I want it to do, taste aside. Because what does it matter what this particular roast tastes like, if I can't replicate it, or control my output from batch to batch? Also, I would like to be able to produce a classic Rao-inspired curve as a baseline roast. If I can reproduce that, and cup it, and find it lacking in some way, **then** I will tweak. Because at that point, I will be able to steer the roast purposely in a certain direction, if that makes any sense.

In other words, I think folks may overestimate my level of proficiency. I still don't really know what I'm doing! :D

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Brewzologist
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#7: Post by Brewzologist »

I'm a nerd so I get your approach; hone your technique and then create your art. But if you haven't tasted any of those roasts I certainly would. They aren't that bad and it may help you identify a general roast level taste target too.

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cjhacker23 (original poster)

#8: Post by cjhacker23 (original poster) »

Brewzologist wrote:Specifically to your roast curves, it looks like you are cutting power a bit too quickly perhaps after first crack starts. Try extending the power change through first crack 5-10 seconds before you decline to the next lower setting.
Okay, I think I get it--basically keep the power steady through the first 10-15 seconds of first crack before lowering it. And then cutting the power altogether as I approach 2nd crack (if I insist on roasting this long) to mitigate the flick at the end. Am I understanding that right?

About the fan: I still don't quite understand what the fan is doing. I had thought that raising the fan brings temp down--but I think I may have that backwards? Is it possible that in these roasts, bumping up the fan to max at the end as the beans approach 2nd crack is actually **increasing** the temp in the roaster, as the beans go endothermic? And if so, perhaps that's another reason to just leave the fan alone, to pick a setting and stick with it throughout.

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Brewzologist
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#9: Post by Brewzologist »

cjhacker23 wrote:Okay, I think I get it--basically keep the power steady through the first 10-15 seconds of first crack before lowering it. And then cutting the power altogether as I approach 2nd crack (if I insist on roasting this long) to mitigate the flick at the end. Am I understanding that right?
Yes, but don't take that as a gospel recommendation! :) What I am trying to say is to look at the power decreases you made from a previous roast, and in the next roast adjust them forward/backward so as to affect the curve the way you want. e.g. if you are crashing after first crack start, carry power longer/hotter before decreasing in your next roast, and vice-versa for the flick. Also, note that the power changes will differ depending on the type and age of bean, current conditions in your environment, etc. What I have is a history of every roast I've done that can be used to guide a future roast, but it's just a guide. You have to keep your hand on the power and make intuitive changes to nail a roast. This takes time and an understanding of your particular roaster. But this is also why I find the ability to follow a previous roast profile in software invaluable for me.
cjhacker23 wrote: About the fan: I still don't quite understand what the fan is doing. I had thought that raising the fan brings temp down--but I think I may have that backwards? Is it possible that in these roasts, bumping up the fan to max at the end as the beans approach 2nd crack is actually **increasing** the temp in the roaster, as the beans go endothermic? And if so, perhaps that's another reason to just leave the fan alone, to pick a setting and stick with it throughout.
In general, the fan in a drum roaster does two things depending on it's speed; it either increases convective heat or cools the roast chamber. And whether it's heating or cooling the chamber can depend on a particular power setting. e.g. at 100% power a 50% fan increases convective heat, but at 50% power a 50% fan may cool the chamber. You can play with this in an empty roaster by trying to maintain a steady BT and see what the effect of fan changes does, but I digress.

For drum roasters, I think it's generally a good idea to set one airflow (based on the lighter trick) to use during a roast and not mess with it. Perhaps just before drop increase fan to evacuate smoke, but that's all. Messing with fan during a roast is an imprecise tool compared to adjusting power. Others can chime in here but it seems pretty common advice for drum roasters on the H-B forum.

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CarefreeBuzzBuzz

#10: Post by CarefreeBuzzBuzz »

He's a nerd; he knows that; I am biased. Switch to Artisan to log your changes and then you can analyze those and decide on when to make adjustments to the next roast and compare the results - both curves on the screen at the same time.
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