Some roasting observations

Discuss roast levels and profiles for espresso, equipment for roasting coffee.
treq10
Posts: 48
Joined: May 13th, 2015

Postby treq10 » Nov 11, 2017, 9:40 am

Hello all,

I have been roasting on a 2KG Buckeye roaster for some time now, and I finally feel like I'm getting the hang of it. I just thought I'd share some of my findings so far so that 1) I can get some feedback on whether I'm on the right track or not and 2) possibly help others who might be going through the same problems I've had.

So here it goes:

1) Start with the best quality beans. Oh man, I started with cheaper coffees, and for the life of me, I couldn't figure out whether the cupping results were a roasting issue or a green bean issue. Once I started sourcing strictly from Nordic Approach (which in China is the most reliable source for traceability and reliability without getting samples), I was able to deduce the issues. So as to eliminate variables, definitely get the most reliably good coffees you can source. If you're in the US, then you have tons of sources for this. Please do not skimp on quality. You will always pay for it in the long run ;)
2) Roast curves all so relative. With my roaster which reads a ton of the faceplate temp (just like Tim Wendelboe's), I realized that I really can't follow any of the curves posted here on this forum or anywhere else. So then what's the solution? 1) Rob Hoos has really helped me a great deal. His emphasis on focusing on different chemical process points has allowed me to think of roasting in a transferable way. 2) Trial and error. Nothing beats the diligence of continually tracking improvement from roast to roast.
3. DTR% (development time ratio) as a concept is BS when comparing one person's method to another. Obviously, within a fixed system (aka Rao's, or Mark Michaelson's for that matter), you can think of development time as a percentage in a relevant way. But from roaster to roaster, coffee to coffee, style to style, the DTR is totally wrong. I messed up so many roasts because I thought the DTR had to fit within a certain window. Some of my roasts go to 25%, others go to 12%. They all taste good based on the coffee & taste profile I'm going for. Coffee roasting should be thought as much more fluid than many people want it to be for the sake of simplification.
4. It's all about your palette. Some like it light, floral, fruity; others dark, bitter, and roasty. Some prefer lots of sugar cane sweetness, others more caramel/chocolate. You are the master of your roasts, so don't let others dictate what tastes good for you. But if you know that there others who have attain your desired flavor profiles, do follow them.
5. Follow your palette to your source. I love lighter, juicier, sweet and fruity tasting coffee. That leads me to favor green coffee sellers like Nordic Approach. Others are more open and variable. I love Sweet Maria's/Coffee Shrub for this reason. They always give you the full gamut of what's possible with a given coffee so that you can buy what you like. Others don't necessarily do this. Find your desired profile and source accordingly.

Next post I'd like to post mainly on technical findings. Hope this helps others!

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hankua
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Postby hankua » Nov 11, 2017, 11:14 am

Thanks for starting a discussion, it's a bit difficult to determine if your in China or NJ? I've also heard from a small artisan roaster in Taiwan, samples were not provided either.

Obviously one cannot blindly follow a curve, but it is useful to compare curves from identical machines and try to figure out what the strategy was behind the roast profile. Personally I don't pay much attention to DTR and there's a newer metric AUC that's at least worth taking a look at in conjunction with the other major landmarks.

If I'm remembering correctly, Rao's DTR is based on his consulting work with the Artisan roasting community and his observations on overall roast quality in the cup. So it may be a bit unfair to say a roast should be dropped at "xyz" DTR rather than executing a 10k profile hitting all the proposed metrics, and it ends up with a 20% DTR.

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FotonDrv
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Joined: October 30th, 2012

Postby FotonDrv » Nov 11, 2017, 12:04 pm

OK, for a newbie like myself, whats AUC?
LMWDP #417. Life is short, so enjoy what you do and what you brew :-)

SJM
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Joined: May 17th, 2007

Postby SJM » Nov 11, 2017, 12:22 pm


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FotonDrv
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Joined: October 30th, 2012

Postby FotonDrv » Nov 11, 2017, 12:23 pm



Ahhhsooo, thank you Susan.
LMWDP #417. Life is short, so enjoy what you do and what you brew :-)

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spromance
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Joined: June 8th, 2017

Postby spromance » Nov 13, 2017, 11:39 pm

I don't have much to add, but just wanted to throw a kudos out there to treq10 - I think that's some really sound advice for beginners/those of us still working at learning and improving!

Two thoughts I thought I'd throw out there too:

Regarding point (1): assuming you've bought good quality, make sure to use it in a reasonable time frame. Early on into roasting, I heard the whole 'greens last forever' mantra and therefore didn't worry about letting certain greens sit 1 year + ...point being, this last summer when I paid to get some one-on-one training from a commercial roaster in Grand Rapids to help assess why my roasts weren't very good, the main thing he identified was that the greens I was using were too old and were contributing baggy taints to the cup. Because I'd never tasted baggy coffee before, I thought that taint was from roasting...long story short: buy good greens and use them up before they age!

To maybe add a point (6): determine early on to not be afraid of wasting coffee in order to learn. If you want an exercise in long-term frustration, obsess over other folks' times, curves, ROR, and DTR (i.e. ignoring all of treq10's earlier points) and push yourself to chase perfection within those confines on your equipment. Or, if you want short-term frustration (from inevitable failures and batches that are pretty wonky) but a quicker learning curve, determine to not fear wasting coffee and just experiment away!! One change at a time, test it all: low batch size, big batch, hot charge, cooler charge, short profile, long profile, light roasts, dark roasts, fast ramp, slow ramp...enjoy the process, cup everything, and take whatever is working for you regardless of whether it 'seems' right...don't fear wasting coffee, don't fear failure and bad batches...intentionally pursue it to embrace and learn from it...I would suggest you'll be producing coffee you love much more quickly this way than by trying to force yourself to fit 'the mould'

jerbear00
Posts: 299
Joined: April 23rd, 2013

Postby jerbear00 » Nov 14, 2017, 2:02 am

The above is really great advice. I could certainly branch out more. I tend to get in a rut. Hit a profile I am pleased with and stop experimenting.

treq10
Posts: 48
Joined: May 13th, 2015

Postby treq10 » Nov 14, 2017, 10:55 am

hankua wrote:Thanks for starting a discussion, it's a bit difficult to determine if your in China or NJ? I've also heard from a small artisan roaster in Taiwan, samples were not provided either.

Obviously one cannot blindly follow a curve, but it is useful to compare curves from identical machines and try to figure out what the strategy was behind the roast profile. Personally I don't pay much attention to DTR and there's a newer metric AUC that's at least worth taking a look at in conjunction with the other major landmarks.

If I'm remembering correctly, Rao's DTR is based on his consulting work with the Artisan roasting community and his observations on overall roast quality in the cup. So it may be a bit unfair to say a roast should be dropped at "xyz" DTR rather than executing a 10k profile hitting all the proposed metrics, and it ends up with a 20% DTR.


Great points! I agree that curves shared by others are super helpful, but I just wanted to emphasize the importance of understanding that everyone's setup is significantly different enough that curves alone will never give enough insight. AUC is cool, but it also is only one piece of a large, complex puzzle. To me, the most important things are when the major chemical reactions happen and when and how the heat is added. If I know the parameters for these two factors, I can translate a roast profile more easily.

Rao's 20% DTR is so specific. Even though it's over 10k samples, it only speaks to his style of roasting, which is great if you find his style to be the most enjoyable. However, it doesn't do much to help us understand roasting as a system, and many of the tools that are available to shape a roast and prevent defects.

treq10
Posts: 48
Joined: May 13th, 2015

Postby treq10 » Nov 14, 2017, 10:57 am

spromance wrote:I don't have much to add, but just wanted to throw a kudos out there to treq10 - I think that's some really sound advice for beginners/those of us still working at learning and improving!

Two thoughts I thought I'd throw out there too:

Regarding point (1): assuming you've bought good quality, make sure to use it in a reasonable time frame. Early on into roasting, I heard the whole 'greens last forever' mantra and therefore didn't worry about letting certain greens sit 1 year + ...point being, this last summer when I paid to get some one-on-one training from a commercial roaster in Grand Rapids to help assess why my roasts weren't very good, the main thing he identified was that the greens I was using were too old and were contributing baggy taints to the cup. Because I'd never tasted baggy coffee before, I thought that taint was from roasting...long story short: buy good greens and use them up before they age!

To maybe add a point (6): determine early on to not be afraid of wasting coffee in order to learn. If you want an exercise in long-term frustration, obsess over other folks' times, curves, ROR, and DTR (i.e. ignoring all of treq10's earlier points) and push yourself to chase perfection within those confines on your equipment. Or, if you want short-term frustration (from inevitable failures and batches that are pretty wonky) but a quicker learning curve, determine to not fear wasting coffee and just experiment away!! One change at a time, test it all: low batch size, big batch, hot charge, cooler charge, short profile, long profile, light roasts, dark roasts, fast ramp, slow ramp...enjoy the process, cup everything, and take whatever is working for you regardless of whether it 'seems' right...don't fear wasting coffee, don't fear failure and bad batches...intentionally pursue it to embrace and learn from it...I would suggest you'll be producing coffee you love much more quickly this way than by trying to force yourself to fit 'the mould'


I completely agree with both points! This is why having a sample roaster would be so helpful. It helps evaluate greens quality and make sure that the waste of testing coffees is as minimal as possible. :)

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hankua
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Joined: April 5th, 2010

Postby hankua » Nov 14, 2017, 2:49 pm

If your saying a Rao's declining heat strategy is just one method, totally agree. And in the Huky realm there are users who goose the gas pressure before the onset of first crack. That being said, if a fixed gas and air strategy works; why not?

 
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