So you want to start roasting? How good are your coffee greens?

Discuss roast levels and profiles for espresso, equipment for roasting coffee.
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#1: Post by luca »

I try to put forward the view that home roasting isn't all smooth sailing, mainly because of the survivorship bias that one can expect on roasting forums. The people that post are the people that roast; not the people that tried it and gave up. They enjoy it, so when a newbie fronts up and asks if they should spend lots of time and money on roasting for themselves, the answer is usually yes.

So what I wanted to do today was to illustrate a problem that you are going to face if you want to start roasting. Let's be honest, you probably don't know your catuai from your castillos, but you're going to have to source green coffee. You're going to read people telling you that they get better results than they can buy. You're going to do a google search and buy some coffee that sounds good, from a webstore that seems credible, maybe based on some user reviews. Then it's going to turn up, and you're going to have no clue how to roast, but you'll give it a shot. And you'll either think that your results are good or bad. Regardless, you're probably not going to have much of a clue if you had bad green coffee, or what the potential of the green coffee that you have is, and if you're oblivious to defective coffee, you might bang your head against the wall for a while being unable to improve your results by not appreciating that your green coffee isn't very good.

Professional green coffee buyers are a thing; they have specific skills and expertise evaluating coffees to try to avoid their roastery being saddled with stuff that doesn't perform as expected. Now of course you can put a sign on your lawn that says "professional coffee roaster" and no one is going to stop you, so it's not like all coffee roasteries have such a dedicated and skilled person, but some do. You don't.

Is this concern overblown? That's for you to figure out, but I bought a wide selection of green coffee from the Australian home roast market recently. I won't go into the taste defects, since they're more subjective, but I have two objective examples of visually diagnosable defects to illustrate the point that bad coffee is a thing. One is some badly insect damaged and pulper nipped coffee (I hand sorted out the defects) where you can see that the coffee has gone mouldy on the cracks and insect holes. Another is a coffee with a lot of "full black" defects easily visible. I roasted and tasted both of these, and, indeed they have a very long aftertaste that is quite dirty and objectionable. (Having said that, I can totally see that at a darker roast level, that would probably fly under the radar, with people thinking it was just roast bitterness.)

For reference, here's an old article from on the old SCAA green grading system (I'm not sure if they have revised this; I think they might use a 350g sample size now, not 300g):

As I said, the pictured coffee are just examples of objective and pretty extreme defects. No doubt y'all will go "those are terrible; I've never seen anything that bad; I buy from reputable sources", but my point is that if you can buy stuff that's this bad, then it's certainly possible to get things with lesser defect, or poor quality.

So, what do you do about it? Well, I guess that, practically, as ever, if you want to improve your coffee quality, you probably ought to do as much benchmarking and tasting of different things as you can to develop your own palate and frame of reference. And if you get clearly visually defective coffees like these, certainly do roast and taste them!

LMWDP #034 | 2011: Q Exam, WBrC #3, Aus Cup Tasting #1 | Insta: @lucacoffeenotes
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Capuchin Monk

#2: Post by Capuchin Monk »

I haven't received green beans looking that bad so far. :shock: Personally, I would return the batch to the seller if that happened to me. As for the visual defects, I noticed more of that (or it appears so) when I buy blends as oppose to single origin. Now that I buy only single origin and do my own blending, I worry less.


#3: Post by LuckyMark »

Great post!

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#4: Post by espressotime »

I've been roasting for 12 years.Simple roaster.Behmor and Gene 101 at the moment.I put 250 grams in the thing,set the temperature at 235 C and roast it till the colour is to my liking.That's it.And my coffee tastes good enough to me.Not better or worse than 90 % of the specialty roasters I sometimes buy a few pounds from.
To me there isn,t much to it. Am I so good? Of course not.Question should be why aren't the pro roasters with there probats etc better ?
Of course I have bought really nice coffees from roasters that tasted amazing. But like I said 90% of them don't convince me.
The green beans are bought at pro roasters. And I trust them to make the right choices for me.One green beans seller has sold bad beans to me a couple of times.They looked good but still didn't taste good.I think they hadbeen to long in storage at his shop.The sort of beans in your pictures I have never encountered.


#5: Post by BodieZoffa »

I personally don't buy into the 'professional' thing as that simply means someone gets paid for what they choose to do, never a guarantee they excel at it. For many years I bought roasted from lots of artisan commercial setups and some were quite good, some were just average for my taste. I will never buy into the theory that the commercial guys do it better as roasting is the same as espresso... if you have the skill set and capable equipment you can achieve anything you want/expect and do so consistently. I also don't buy into the 'certified' system as that simply means someone is following rules set before them to an 'established' standard. I question most of things in life like that as there is more than one way to reach the desired end result and choose to not follow what others do. Long ago I knew if others could roast and get excellent results I damn sure could and things just took off.

It is far more involved than just turning green beans brown, but quite doable with determination and patience. I source quality green from a handful of reputable sellers and have not yet received anything I'd consider trash by any means. I built my setup to give me infinite control of temperature/agitation, airflow to a decent level, have it setup to give me constant visual/smell to pick up on development changes in real time and I control it all manually. No lame software doing the work for me as I take a seat of the pants approach and observe every second of every batch. Is every batch perfect? Of course not, but on a scale of 1-10 the typical batch is say a 7, an occasional batch an 8-9 and once in a green moon a solid 10. I will gladly say that I clearly save $ roasting my own for my fairly heavy consumption. All said/done my setup has long paid for itself and just the cost of green at this point. I don't buy into the 'well time is money so count your time involved too' as if I wasn't roasting I'd be using that time for other things, so not like that should really be considered when it's something that is a part of life you look forward to. Not a hobby for me, but a daily lifestyle and that's how I roll! Only regret is not starting it sooner than I did and I never plan to buy roasted coffee again.

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#6: Post by mgrayson »

Survivorship bias is present in *any* endeavor. I have three major hobbies - piano, photography, and roasting. (I'm not counting coffee as a hobby - it is life itself.) With each one, I've had breaks of a decade or more where I was too frustrated to continue. But teachers change. Technology changes. Time and opportunity change.

Roasting takes work, even with the most computerized systems. And I'm not very good at it. But the results are different enough and interesting enough over what I've found to buy that - for now - it's enjoyable and worthwhile.

As to the main point - good greens - I couldn't agree more. Top quality isn't *that* expensive, and it sure is rewarding.


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#7: Post by mkane »

If you've had great coffee from a pro you wouldn't think it was just a thing. Always striving for perfection or I'd just quit.


#8: Post by BodieZoffa » replying to mkane »

Personally have never been truly impressed with much of what I've bought roasted from ANY company and have NEVER been impressed with espresso from ANY shop. Some things can be done far better at home with complete control start-finish. People should never doubt themselves and just make it happen!


#9: Post by Trjelenc »

luca wrote: The people that post are the people that roast;

Great, now this line is going to be stuck in my head forever


#10: Post by Trjelenc »

BodieZoffa wrote:Personally have never been truly impressed with much of what I've bought roasted from ANY company and have NEVER been impressed with espresso from ANY shop. Some things can be done far better at home with complete control start-finish. People should never doubt themselves and just make it happen!

Man, either you live in a coffee desert or I am a pitiful home roaster. I'm constantly getting batch brews from local roasters that just floor me. I'm happy with 80% of my roasts, but when I taste some of these professional roasts, it's like I'm tasting an extra dimension compared to my own coffee.

And to tie it back to the original post, I always wonder if the beans that some of these places use are much better than Sweet Maria's and Happy Mugs offerings that I'm buying. I never have found damage like above, but I'm curious if it's a similar quality taste-wise.