This is very interesting - I've been roasting the Huila Palestina pink bourbon from Burmans recently, with - by my own rather low standards - good success. I've never picked through the beans, but either my palate isn't up to detecting the defects, or I've been lucky.

Although this was rather on the expensive side compared to what I'm normally roasting, i think this is actually a great bean for a novice roaster like me. It reacts in a very predictable manner, and i can experiment with different phase lengths and roast levels to modulate acidity, sweetness and other in the cup proprieties. I've not had a bad roast from it, and have dropped it from 410F to 430F.

This thread has me wondering, how to select beans like this again in the future? Easy roasting with little by way of defects and a wide range of possibilities for output roast level etc. Should i be looking for specific origins? Regions? Varietals?

Bourbons seem to roast predictably. Captains Coffee usually has a few.

What can you tell from these greens?

If I haven't made this point clearly enough, let me repeat it: the absence of visual defects doesn't mean that the coffee is defect free or even good. The green can look picture perfect and still have defects, problems or be of poor quality. I only posted photos of extreme visual defects based on the Scaa guidelines to give an illustrative example of a subset of defective coffee; not to give an exhaustive coverage of all of it.

CarefreeBuzzBuzz wrote:What can you tell from these greens?

I can positively say they've not been roasted yet and they don't appear to have obvious defects. But sadly, that contains no useful information and I'm not sure one can glean anything else from that picture.

The look to me like the moisture content is high.

Screen size varies quite a bit.

ira wrote:I can positively say they've not been roasted yet and they don't appear to have obvious defects. But sadly, that contains no useful information and I'm not sure one can glean anything else from that picture.

Oh well yes!! I better roast them. That's very useful. Tomorrow I'll roast them. Defects aside my focus will be on drop temps.

Luca, thank you for hosting a very helpful discussion here. A hidden treasure was your mentioning the drop in Kenyan quality recently and linking the Christopher Feran article. For anyone who didn't open that link, you have an assignment. To summarize from memory and correct me if I miss something, Christopher does a deep dive into the effects on quality of a sourcing and processing system that was initiated in colonial times, is not rewarding farmers for quality or separating out the best lots. With the size of crops reduced, the double washing and drying system that could be done efficiently in large washing "factories" is no longer being followed. The double washing system helped quality and created a signature taste. Christopher discusses the technical reasons for this. In other words, an outmoded national system for organizing coffee production is now hurting the quality of Kenyan coffees. Back to the point of this topic, the greens aren't as good. Home roasters who don't know this might doubt their technique.

About that Colombian Huila Pink Bourbon coffee, I was one of those who bought on others' recommendations and was disappointed with a meh coffee that I have to develop sufficiently that I'm not emphasizing origin flavors. Thanks to this thread, I'm paying more attention to the many defective beans. But there's also a professional consensus that home roasters like me may not know. Am I getting a lesser lot? Is something different going on in the coffee industry in that part of Colombia?

Part of my learning curve has been adjusting my roast to bring out the best in the coffees I have, even if the greens are less than excellent. I would expect only fresh, specialty grade greens in a good crop year to shine in a lighter roast. I am also learning that freshness makes a big difference and will either roast my recent greens sooner or seal and freeze the very best ones to roast at my leisure. I am also trying to buy the newest arrivals. A Christopher Feran article mentioned in another thread taught me about how wild yeasts and other organisms can quickly degrade excellent greens in a much shorter time window than I'd learned to expect.

https://christopherferan.com/2020/01/24 ... at-dinner/

luca wrote:If I haven't made this point clearly enough, let me repeat it: the absence of visual defects doesn't mean that the coffee is defect free or even good. The green can look picture perfect and still have defects, problems or be of poor quality. I only posted photos of extreme visual defects based on the Scaa guidelines to give an illustrative example of a subset of defective coffee; not to give an exhaustive coverage of all of it.

Back on the topic of defects and how they relate to actual post roast in the cup flavour I wonder if Luca might be able to tell me what defect (roast or green) might cause a papery/cardboard flavour. It reminds me very much of TCA/corked flavour in wine. This is a coffee (washed Guatemalan/Ethiopian blend) I've had many times and none of the other brewing parameters have changed. Assume an EY% of ~21% so it's not under extracted.

^^^^R0R flatline maybe aka baked