“Seeing through” roasts

Photo by Liz Clayton





About 10 years ago I participated in a cupping in Seattle of 20 Panamanian coffees from an online auction.  I had a very different tasting experience from that of the other professionals in the room that day.  While the coffees on display were all clean and high quality, I found ranking them unusually difficult because the quality of the sample roasts varied so much.


Most of the roasts were baked and roast development on the table varied wildly.  Some samples benefited from having been roasted well, while other samples were flat, roasty, or vegetal.  I quietly polled several people in the room, and no one else seemed to notice the problem, or to care.  Several of those “professionals” thought I was just “too picky.”  Funny, I thought being picky was the point of cupping green for purchase.  Coffee pros have called me “too picky” many times, most notably for criticizing poorly designed, trendy equipment, years ago for weighing the water in a cupping, and often for remarking about rancidity in coffee.  I think one professional calling another “too picky” about quality usually says more about the judge than the judged.


I realized that day that my experience of coffee differs from that of most other professionals on a regular basis.  Compared to most, I’m relatively more tuned in to extraction and roast quality, and less tuned in to green quality.  Please don’t misunderstand: I’m plenty picky about green quality, but I have no interest in drinking a poorly-roasted coffee just because the green was scored 89.  My experience drinking third-wave coffee makes me think I’m in the minority.


For me, the “noise” of bad roasting often gets in the way of my ability to enjoy a coffee and to “see through” to the quality of the green.  It’s still easy enough to rank a poorly roasted 89 over a well-roasted 86,  but when you’re deciding between a few lots of similar quality (let’s say they’re all 86’s and 87’s), and the roast quality of the samples varies quite a bit, how do you know if, and how much, the roast quality is influencing your buying decision?


Given that we must roast green coffee to evaluate its flavor, there’s no way to completely separate what cup traits are due to “roast” and which are due to “green.”  Yet, when we buy green coffee, we choose lots by cupping roasted samples, and seem to largely ignore the effect of the roast on the traits expressed in the cup.  I can’t tell you how many times I’ve seen professionals choose among coffees with nearly identical green scores, and select the one that happened to have been roasted best, while believing they chose the best lot of green.


I’d like to speculate that there are two separate issues at play here:


1. Some pros “see through” roast and extraction to the green quality better than others, while others are more tuned in to roast and extraction quality.  The “see-through” types make better green buyers, while the roast/extraction obsessives probably make better roasters.

2. Many green-buying decisions are influenced by variations in roast quality among samples, but few seem to notice or talk about it. (Variation in extraction quality is usually not an issue in cupping.)


I’ve had dozens of clients who, prior to hiring me, said “I’m very happy with my roasting but simply want to see if there are ways to improve a little.”  Many of those clients were very skilled at evaluating green coffee, but somehow didn’t notice that they routinely baked or underdeveloped roasts, and didn’t bring out the full potential of their lovely green coffees.  While working together, all of those clients eventually had an “aha” moment when they began to understand what baking was doing to their coffees’ sweetness, and what underdevelopment was doing to their coffees’ fruitiness.


The good news is that, like green evaluation, identifying roast defects is learnable.  The bad news is that most of us don’t know what we don’t know, and it’s a skill almost all of us could, and should, improve.


I have a friend whose palate for green I hold in the highest regard.  His sense of smell is extraordinary, and he “sees through” roasts and extractions like no one else I know.  However, his enjoyment of a coffee is relatively unaffected by roast and extraction quality. (He does have a strong preference for lighter roasts, just not as much as for the quality of that light roast.) He and I couldn’t be more different in that way; few things in coffee disappoint me more than ordering a 90+ point Kenya and being served a sour, baked cup with mere hints of the massive, ripe fruit that could have been.  That sour, baked cup is the norm in third-wave coffee, often at the bargain price $6 for that disappointing experience :). I’d gladly pay $18 per cup for a Kenya done well, rather than buying three cups and throwing them all out in frustration.  (That’s a typical day of cafe-hopping in any big city for me.)


Diagram Key:

The “Roast” circle contains qualities that can be brought out of any green coffee to a similar degree by roasting.
The “Green” circle includes qualities that are not available from all coffees.
The Intersection of the circles contains traits that all coffees offer to varying degrees, and whose expression is enhanced or muted by roasting.


I’ve created this diagram to begin a discussion about how to differentiate which cup qualities are due to “roast” and which are due to “green.”  Of course, all of the qualities in the diagram derive from roasting green coffee, so I’m abusing Mr. Venn’s elegant creation a little.  I realize these classifications are highly debatable, so please take them in stride.


I’d love your comments on this issue… I’m sure my perspective is skewed by being more sensitive to roast and extraction than I am to green, at least compared to most other professionals.  I’m especially interested in reading comments by those who are more green-sensitive.


If you’re keen to discuss this topic and more like it, and happen to be Europe next month, I’m offering Roasting Masterclasses in Budapest on June 12th and 13th. Click here for details

50 thoughts on ““Seeing through” roasts

  1. The issue here is maybe 10% of the coffee drinkers knows what’s a good coffee from a not so good coffee…
    Then 10% of roasters knows how to roast optimally (close to perfect).
    Not many people left…
    I do like greens when it doesn’t taste like vegetables, I always go in a coffee shop with my big “please surprise me” spirit… fails most of the time… I want my juicy brewycino! (Come on now…)
    I have yet tasted high extraction coffee so I cannot comment, not enough experience…
    But still this world of coffee and potential in it is magnificent!
    Please roasters! Please…

  2. Thanks for another write up Scott,

    I was wondering what the added value of (ha) and (haha) in the circle diagram are meant to represent? Are they negative or overly obvious in your opinion?

    Also, I am very interested in taking a Europe class, I’m just wondering if you will make a stop in the Benelux/Germany region? If not then I’ll make plans for coming to Budapest.

    • Hi Max,
      I was just making fun of the ubiquity of those tasting notes… If you had never consumed a coffee in your life and you read the tasting notes on 100s of third-wave coffee bags, you’d think coffee must taste like a cross between red wine and various fruity desserts, especially those made with Meyer Lemon or stone fruits. You’d never think the predominant flavors were roasty, biter, and sour, with just a hint of sweetness.

      The only classes I’ll be offering in Europe this year will be in London and Budapest. No offense to Germany– I love it there 🙂

      I hope to see you in Budapest.


      • Scott,

        You say above, “You’d never think the predominant flavors were roasty, biter, and sour, with just a hint of sweetness.”

        Why doesn’t “sweet” appear in the diagram?


        • Because I don’t see it as a predominant coffee flavor. Give a random person in the street a cup of black coffee: what are the odds they would categorize it as sweet?

          I’m guessing almost no one would.

          • But “fruity” is a “predominant” effect of roasting?

            Not my experience. But I’m not a random sample, for sure.


          • It’s a good point– I think high-quality, washed coffees roasted lightly (the only coffee I choose to drink) is usually fruity, and therefore I’m biased and forgetting that most coffee is far from fruity :0. Thanks for noticing.

  3. I’m pretty sure I’m more roast/extraction sensitive as well :). Nice initiative anyway !

    For you astringency is a roast defect ?

    • Astringency is usually an issue of overextraction, whether due to channeling, too many fines, or general overextraction. But if you drastically underdevelop a coffee, especially with a very fast roast, the coffee can be astringent regardless of extraction.

      • Ok thanks. So one prerequisite of your diagram is to have an good (enough ?) extraction. This way, defects and qualities will only be roast/green related.

        • I can’t say defects and qualities will ever be “only” roast or green related. But if you’re cupping at a reasonable extraction level, that’s good enough. Immersion brews like cupping are pretty easy as far as getting an even extraction and being consistent. Percolation brewing (filter, espresso, etc) is much more erratic and more often leads to astringency, etc, so if you’re evaluating roasts by cupping, extraction issues are less likely to get in the way.

  4. I use a similar system where I classify roast flavours and inherent green flavours separately in my head. Then when I cup through the coffees I try to ignore the roast flavours if im evaluating green quality and focus only on the green flavours.

    Similarly i try to ignore the green flavours and focus on roast flavours when evaluating a roast profile. But its not always so easy because they are very intertwined at times and the roast can affect the intensity and even presence of certain green flavours. Especially when they are of similar qualities as you mentioned then it does make things more tricky. A little thing ive noticed is the relationship with the dry aroma, if im evaluating two similar quality coffees and both have great dry aromas but one cup may not have the same flavours as it’s aromas or is less intense then I might attribute it to a possible roast fault.

    How do you normally go about dealing with these issues scott?

    • Hi Kenneth,
      I agree about the dry aroma. The best dry aroma I’ve smelled in the past year was extraordinary but the roast was so baked I couldn’t drink the coffee.

      I don’t have an answer for you. All you can do is try to sample roast well, spend decades practicing roasting and cupping blindly, and be sensible in your approach, as you are doing now.

  5. Hi Scott,

    Great article as usual! I have a question which is slightly off topic:

    I just started roasting a new espresso (Washed Rwandan from Nkora) roast starts off great and ROR is steadily declining up to first crack then it completely loses energy and stalls at 394F. I’ve increased the charged temperature but the same thing is happening and I’ve even increased the gas quite significantly after first crack but it still takes a massive dive then at 398F speeds up again and I reach end temperture way too fast but the ROR is showing the lick of death. What should I do?

    • Hi Bryce,
      I’m sorry, I don’t really offer to fix people’s roasting issues with the blog. And I’d need more information from you to solve this. But likely you need A LOT more energy mid-roast and to taper off the gas more than usual, as of about 2 minutes before FC. In many such situations like yours, the batch size may be too large.

  6. I agree with you. As a roaster who cups every day for roasted, finished goods quality, I find that I am easily distracted by roasting issues when cupping for green coffee purchasing. It makes it harder to focus on the green coffee quality.

  7. Thanks for the post Scott, as a roaster with green buying responsibilities I’ve thought about this quite often, especially when attending cuppings outside of my own workplace or when receiving roasted samples from green suppliers… I’m always hesitant to make purchasing decisions when I haven’t roasted the coffee myself, not because I think my sample roasting is somehow superior but because I can take notes and have data and more information to correlate to the cup results.

    I find the majority of people are sample roasting on the very light side, accepting the risk of underdeveloped flavours that comes with that, and letting the green coffee quality “speak for itself”. If all the samples are roasted in this way then it does serve that purpose, but I’m with you in that I find the peanutty/grassy/raw flavours so unpleasant that it affects my ability to assess the positive attributes of the coffee.

    Obviously the problem is that with many samples there is 200 grams of coffee and we only get one or two attempts at trying to get to know a coffee, but I prefer to go a little darker/more developed, even if it risks a tiny bit of “roastyness” or bitterness compared to the super light roasts (especially without the use of a bean probe or RoR in most sample roasters) because I find it easier to “see through” that type of roast than one that is underdeveloped.

    • Hi Ben,
      Thanks for the thoughtful comment. As usual, I think we’re on the same page. I feel the same way about others’ sample roasts– it’s not that mine are better, it’s that when you’ve done the sample roasting yourself, you have context and confidence in how the roasts may affect the cup.

      I’ve given up on traditional sample roasters due to the difficulty of installing a bean probe in them in a good spot that will record quality bean data in Cropster. These days I favor little machines like the Mill City or Bella that are designed, and work, much more like production roasters, and facilitate quality bean data. A 200g batch records quite well in a Mill City 500g machine, for instance. I’ve never used an Ikawa, though I imagine that it can record quality data and roast more consistently than a typical sample roaster.

  8. Interesting article Scott! As someone that roasts on a very small 1kg Mill City roaster I always wondered how it’s possible to evaluate green coffee from sample roasters without being able to really see that the roasts are all similar. Otherwise it’s like you’re comparing apples to oranges.

  9. Scott, is there a roaster you’d recommend as an example of what a good roast tastes like? I feel like I need to be calibrated.

  10. I’m a producer from Thailand. I agree with this completely. We pitched our coffee to many roasters around the world this year. The range of scores is a 10-point spread for our main lot, for the exact same coffee. The majority of the feedbacks is 84-85, but we get a 78 and 87 as well. I attribute the wide spread in scores to the variation in sample roasting. From my experience pitching the coffee for the past few years (and we are making some in road into the specialty market), the type of cuppers and their coffee culture matter a lot as well. Each seem to have their own way of sample roasting. Importers will almost always score lower, and roast lighter, than roasters. Roasters who are bigger and deal with a wide range of coffees score higher than micro roasters whose preference is bright African coffees. New Zealand’s cuppers whose espresso culture is very strong will score our coffee higher than the Scandinavians. My experience is consistent with what you’ve described. For the low end of the score, the feedbacks were typically vegetal, grassy, and astringency. The higher end we get lemon and stone fruits (haha)…Thanks so much for raising this point. I don’t have many people to vent to about this.

    • Hi Fuadi,
      That is interesting. Thank you for sharing.

      i know some people, all extremely good green buyers, who seem to be able to pinpoint a score for a coffee, almost no matter how it was roasted. But I think the rest of us are influenced to varying degrees by roast qualities.

  11. Very interesting article. I can honestly say the single biggest thing that has improved our coffee offeing (after vst tools and cropster) is having an ikawa.

    They are not perfect and many people end up roasting “flicks” into their coffee as it’s an environmental curve and not a bean curve but the consistency is second to none. It gives a very even playing field to all coffees and you can somewhat forget about roast once you have dialed in a curve to your tastes, which is great for the too picky types.

    I have one standard curve that I use for any coffee and it works for at least 90% of them. Definitely worth getting your hands on one to try and am more then happy to share profiles.

      • I do not just yet. One could easily get an”exhaust” read out on cropster without having to drill thru the glass faceplate and then combine that with the “heater %” from the exported roast data so get a pretty good idea of what is acrually going on. Cheers for sparking an idea

  12. I don’t get time to do much sample roasting because of the many caps I wear on the farm, and because of that I don’t feel that cupping is going to be effecticve as it should be, so I don’t do much standard cupping. Roasting only our own single Origin, and being primarily a green bean producing company rather than a roasting outfit, means we know the green bean intimately already, and then seeing that what matters is the quality of the espresso roasts that we only really do, cupping focus is relegated mostly to the actual finally blended customer product – the blend being batches of different levels of roast (3 0r 4) leading up to and just on 2nd crack. Each batch of the blend I will cup separately, but again only as espresso.

    • And if I may add, so much of a good coffee experience for most people is for the hour or two or three after consumption. Tasting during cupping lasts for seconds or minutes at best and bypasses the linger effect which is so very important on the train on the way to work after that morning coffee. I find that not all coffees that cup very well initially have that carry over effect, eve when properly roasted and extracted.

      • Hi Bernard,
        Interesting point. I often feel like cupping misses some of the enjoyment I sometimes get from drinking a coffee in a more relaxed manner.

  13. As a dedicated coffee amateur, I had been wondering about this topic lately. With as much effort/focus as I put into roasting my beans the best I can, I often find myself with a given batch wondering whether it’s me or the beans that are making it a good/mediocre/great/awful cup. Quick roasting samples at a farm or CoOp in XXX doesn’t seem like it would necessarily give the best roast consistently.

    Sounds like some Q graders can roll with it, and others can’t always differentiate the bean from the roast. That’s interesting in and of itself. If nothing else, it demonstrates to me that I’m right in only trusting a few bean distributors, and being skeptical when I get off-beans from places that I don’t know as well.

    Thanks for the post. Informative as usual.

  14. Very intersting theme. I am convinced that there are palates that can discern more and better than others, due to
    born in skills or (and) to experience and learning.
    It is a big mystery to me, when I should assign a flavor to the green or to the roast or to preparation.
    Very often different roasts of the same beans are of nearly identical taste to me.
    So one cannot improve roasting skills without improving tasting skills before. I strongly suggest that I belong to the baked group as well.
    I wish you great days in Budapest!

    • Hi Erhard,
      I believe you can improve your roasting skills without improving your palate. Surely, even if your palate never improves, you do not feel your roasts are perfect. Do you? It doesn’t require an improved palate to see ways to improve roasts, unless you say you can never tell the differences between roasts, and they all seem perfect to you. I hope that makes sense.

      • “So one cannot improve roasting skills without improving tasting skills before.”

        I would say: one cannot do without the other!
        There’s some interplay at stake here 🙂


        • Norman,
          Why can’t one improve one’s roasting without improving one’s tasting skills first? For instance, if your tasting skill doesn’t change, but you figure out how to avoid the crash at FC, you will have improved your roasting without changing your tasting skills.

  15. Hi Scott:

    If a change of subject is ok here, would you be willing to discuss percentage weight loss from roasting? Personally I’ve experienced a range of 14% to 20%, depending on home roasters and on roasting curves. I’ve had both good and bad tasting coffee over much of this range.


    • Hi Louis,
      While I could generalize and say that 14% is a light roast and 20% is certainly very dark, for a given coffee, your “ideal” weight loss will depend in great part on the coffee’s initial moisture content. As well, if you roast two batches of a coffee to identical outer bean color and the batches’ weight losses were different, you can assume the batch with the higher weight loss was more developed.

  16. Dear Mr. Rao

    Is there any way to purchase your books “Everything But Espresso” and “The Coffee Roaster’s Companion” as digital copies? I live in Belarus and I’m afraid that due to our customs and postal regulations their delivery will cost me a fortune. And there is no way to find these books here – even the Russian edition of “The Professional Barista’s Handbook” is out of print (hopefully it is possible to find it in the library).

    Of course I am ready to pay the full price of the books to you as well as the cost of the international delivery of two books.

    • Hi Gleb,
      I’m sorry to say I don’t offer digital versions of them. I wrote one short ebook as a test of selling ebooks, and so much about it was problematic, especially that Amazon takes 70% of the revenue from such a book. I appreciate your willingness to pay the full price, etc for the ebook, but I’m afraid I can’t offer that at this moment.

      Kind regards,
      Scott Rao

  17. Hey Scott,

    Great post, and conveniently enough something we were discussing this morning in the roastery after a cupping. We were cupping for a coffee which for about 90% of it’s use will be through espresso. So after the cupping we decided to pull some shots. One coffee was wayyyyy more soluble than the other which obviously points towards the roast, and we felt the less soluble coffee was being unfairly evaluated due to the roast being far from optimal. We use a generic profile for sample roasting for all coffee. We do take roast defects in account though and we comment of the fact it could be a roast defect rather than a green. We also have separate score sheets for green and roasting evaluation which I guess you could do from your diagram as well. We are only human though and it is really difficult at times to try and see past roast so if we think we made a mess of a roast we discard the sample, which is a shame. We were thinking of maybe getting an Ikawa or maybe trying to improve our Probat sample roaster by adding better probes. Would you recommend putting time into improving the sample roasting, or focusing on improving our palates and “seeing through roasts”? Any input would be appreciated.

    Cheers Scott

    • Hi Darren,
      Certainly optimizing your sample roasting and getting better sample-roast data would be a good first step. I prefer to rely as little as possible on my skills, and make any task as easy as possible to improve my results. If you can get a bean probe into the bean mass in your probat sampler, i’d try that first, before investing $3000 in a new sample roaster.

      Best of luck

  18. I try to be very consistent when sample roasting, but I sometimes take into account the type of coffee, the density and processing method when I choose how to roast a sample. Though I am torn about this. Is it more important to get the best one can out of a green coffee, if one knows it should be roasted differently based on previous experience and knowledge, or should one use a standard roast profile for all coffees regardless of the green?
    It would be interesting to hear your point of view on this.

    On a separate note, but more related to the blog article:
    When I cup for buying, I try to ignore any roast defects if any, and “see through the roast” to understand the potential of the green: flavors, sweetness, body, finish, mouth feel. I examine the number of defects in the green and the roasted green and this sometimes influences my decisions. Sometimes I will buy a green coffee despite some more defects, because the cup profile was better despite them. (I also pick out the obvious defects to taste the coffee, I am small enough, I can still pick out defects in my production roasts, so if the green is good enough, I am willing to do this.)
    When I profile roast, I cup to understand the roasting of a coffee; I want to know how my roasting has affected the coffee and what I might need to do differently or keep the same.
    I do not have enough training to score the coffees and I am not sure it would help me or mean anything to customers etc (But it could be good to learn this…there is always more to learn…)

    Thanks for being so good about responding to comments. 😀

    • Michel,

      I think it’s necessary to adapt your sample-roasting method to the coffee while attempting to create somewhat-similar roasts. It seems that’s what you’re already doing. Simply applying the same temperatures or gas settings to every coffee would not be wise.

  19. Hi Scott Rao, great blog !
    Scott, everybody needs a reference about very good roasted coffee, right? I mean if one never tasted a very good roasted coffee how could one know their own mistakes. Could you recommend me a excelente coffee to taste . I don’t know it I ever taste a really really good coffee . I have to buy online .

    Thanks !
    Congrats for the blog!

    • Hi Elvio,
      I’m sorry, I won’t publicly recommend roasters on the blog, except on the chance that I personally experience a coffee I enjoy and want to mention it.

  20. This kind of makes me laugh. I’m a very small roaster, without much contact with the industry (too busy for that). Sample roasting is the bane of my existence: I roast on a San Franciscan 6lb machine, and don’t have a sample roaster. When 4oz samples show up, I cry, haha, it’s hard to pull off a good roast with 4oz in a 6lb machine. I’ve always known I’m missing out on great coffees, and probably not choosing the best one on the table at any given time; I’m choosing the one I roasted best, many times. I do try to see through the roast, and sometimes I think I succeed, but yeah, it ain’t easy.

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