Tasting the three main green coffee defects

Discuss flavors, brew temperatures, blending, and cupping notes.
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luca
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#1: Post by luca » Aug 27, 2019, 6:40 am

Background

Many years ago, when I worked part time at Veneziano Coffee roastery's "First Pour" cafe, one of the baristas on the competition team was the wonderful Craig Simon. Flash forward ten or fifteen years and Craig has won the Australian barista championships multiple times, become a Q-grader instructor and has even spent time organising processing of some very high end green coffee.

The market has also changed dramatically. Twenty years ago, having any sort of coffee roastery with a roaster smaller than about 50kg seemed absurd. Fifteen years ago, we really started to see the cafe/roastery model take off, with 5-12kg roasters. In the last five years or so, we have now started to see people set up collective roasteries, where cafes can hire time on a coffee roaster without having to commit to the capital costs of their own roasting space and their own roasting equipment. Against this background, Craig has now started his own business, Criteria Coffee, which is a mix of collective roasting space, his own micro roastery with wholesale and retail sales and training room.

Intro to scoring defects

Last week, Criteria Coffee hosted a tasting of three samples that CQI uses to teach Q graders to recognise mould, ferment and phenolic defects. It was only a $15 event, so it jammed out and attracted a few home baristas as well as industry types who are just getting started. The event ran as follows. First, Craig did a refresher/intro to the CQI Q grader score sheet. An important difference between that score sheet and the ACE Cup of Excellence score sheet is the three sets of "yes/no" scores, which the ACE sheet doesn't use. Whilst in both the Cup of Excellence and the CQI grading systems, five bowls of the same coffee are evaluated to try to give scorers a good chance to pick up variations, the Q grading sheet asks you to evaluate uniformity, sweetness and cleanliness as tick boxes. There are two points per cup and they are yes/nos. If a cup isn't clean, isn't sweet, or isn't uniform, then it doesn't get the two points. (The CQI doesn't give higher points for more sweetness.) If one cup is defective, it probably won't be the same as the other four, so the coffee will lose 2 points for uniformity as well as losing 2 points for cleanliness. If it is at "fault" level, the coffee loses another 2 points and if it is at "taint" level, the coffee loses 4 points instead. So, even though a "taint" might only subtract 2 points, the coffee will probably lose a minimum of 6 points. In practical terms, the vast majority of coffees that lose that many points will not be good enough for the other attributes to drag them up into specialty coffee classification. The consequence may be that the lot is rejected, which may be a significant financial hit for the producer and/or importer/distributor. Equally, if roasters and importers don't do their own QC properly, the consequence may be that customers end up drinking it. So this is an exercise that needs to be conducted carefully, fairly and with respect for everyone in the supply chain. Here's a snap of Craig giving the intro:


Image



In the cup

In the second part, we cupped four bowls; one being a control and the other three demoing each defect. They tasted as follows:
  • Phenolic: Dirty/band-aid/iodine/chemical/rough/bitter/astringent.
  • Ferment: White vinegar.
  • Mould: Vegetal, musty, earthy.
I usually like to focus on aftertaste to try to pick up defects. The ferment defect sample didn't have much of an aftertaste. To be honest, it wasn't actually all that unpleasant, though it did feel like a sort of clinically very perfect example of ferment - in practice, a lot of ferment occurs alongside other ferment-derived flavours other than acetic acid; sometimes I think that the natural processed coffees that I really don't like remind me of the juice that drains out of a really full garbage bag on a hot summer's day. The phenolic cup had a longer aftertaste and I guess the hallmark of it is that it is the thing that tastes the least like it comes from nature; it tastes distinctly non-coffee and sort of reminds me of stripped wine that has lost its fruit character. The mouldy cup was the least subtle of all, with an aftertaste that was still there minutes after.

The exam

To wrap up, we moved on to cupping six different coffees, which is to say five cups of each of six coffees. We didn't take the session all that seriously, just focussing on identifying the defects rather than fully scoring. We went over the 30 cups several times over about an hour and, as is usually the case in blind cuppings, even the most opinionated people in the room all of a sudden became timid when asked to identify things. Craig only hid four defects on the table - one phenolic, one ferment and two mouldy. The phenolic and the first mouldy cup were pretty easy to identify. Actually, you didn't even have to taste the cups to work out which one was the first mouldy cup - people couldn't help themselves from saying "ugh" after tasting it. The second mouldy cup was hidden immediately after the first and in speeding over it, I think I just assumed that the aftertaste from the first mouldy cup was continuing! Craig hid the ferment defect in the first cup of a natural processed coffee that was close to being over fermented anyway, and he further made it difficult by placing that coffee right after a rather smart tasting and clean honey processed Kenyan, so it was particularly difficult to find. Over three passes, one of my friends and I probably spent about 20 minutes going back and forward over that particular set of five cups, so we were mightily relieved to find that we got it right. At the end, Craig also asked us to identify if any of the coffees were repeated, which the room was able to do pretty easily.

With the hard work over, we knocked off with some beer and an airpot of of filter coffee made from Craig's leftover filter roasts. Whilst I personally don't really like the natural processed coffees that Craig had on offer, I was delighted to taste that all of the roasts were vibrant, expressive and well-developed light/filter roasts, with no grassiness in sight. Craig mentioned that he isn't taking his espresso roasts that much further than that, but I didn't get to taste any.

But what does this mean for us?

If you ask your local roastery about their QC program, you're pretty likely to get some waffle about them only sourcing the highest quality. Some roasteries may also rely on their green suppliers doing the work for them. So what the industry would like you to think is that if you're buying from somewhere that holds itself out as selling "specialty coffee", you never need to worry about green coffee defects. Just looking at this year and at the coffee that I have tasted, that's probably mainly true, but cupping retail coffee with H-B members this year, we have come across phenolics, mould, ferment and also another earthy defect that probably wasn't mould, nor was it potato defect, but was definitely something wrong. The roast defects that we have tasted this year (ie. grassy, charred or baked) have probably outnumbered the green defects at least 4:1. We haven't had many natural processed coffees on the table, but it may well be that if I bought more of them, I would have tasted still more green defects this year. So I suppose that the take home message is that they are out there and they are a possibility.

What to do if you buy a defective bag of coffee is a good question, and one that I'm not going to tackle in this post!
LMWDP #034 | 2011: Q Grader Exam, Brewer's Cup #3, Australian Cup Tasting #1
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mathof

#2: Post by mathof » Aug 27, 2019, 11:13 am

Please excuse my naivety, but what is cleanliness in coffee? Is it a synonym for clarity of flavour?

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TomC
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#3: Post by TomC » Aug 27, 2019, 12:28 pm

mathof wrote:Please excuse my naivety, but what is cleanliness in coffee? Is it a synonym for clarity of flavour?
Straight from SCA:
Clean Cup | Clean Cup refers to a lack of interfering negative impressions from first ingestion to final aftertaste, a
"transparency" of cup. In evaluating this attribute, notice the total flavor experience from the time of the initial ingestion to final swallowing or expectoration. Any non-coffee like tastes or aromas will disqualify an individual cup. 2 points are awarded for each cup displaying the attribute of Clean Cup.
https://www.scaa.org/PDF/resources/cupp ... tocols.pdf

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RapidCoffee
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#4: Post by RapidCoffee » Aug 27, 2019, 12:36 pm

Great post, Luca! I wish there were similar coffee tasting/rating opportunities available in my area.

Or maybe not: "the juice that drains out of a really full garbage bag on a hot summer's day" :P
John

mathof

#5: Post by mathof » Aug 28, 2019, 5:31 pm

Thank you for this. I would once have thought that blueberry, for example, was a non-coffee like taste but I know better now. You'd have to know the range of actual coffee like tastes to use this definition, but I suppose it's meant for those who do.

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Almico
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#6: Post by Almico » Aug 30, 2019, 10:34 am

luca wrote: We went over the 30 cups several times over about an hour and, as is usually the case in blind cuppings, even the most opinionated people in the room all of a sudden became timid when asked to identify things.
That's oh so true. Many an overblown coffee ego gets deflated over a cupping table with people that really know what they are doing.

I get asked all the time if I have ever been to origin, as if that is some right of passage for a coffee roaster. OK, it might be fun to visit, but as a process of selecting coffees to offer at my bar, no thank you. That ordeal is much better left to Q-graders that do it for a living.

I use 3-4 importers for my coffee. All my reps are Q-graders. I am not. They spend months during any given year in the fields selecting coffees and bringing home the best of their efforts. How many coffee farms would I get to visit if I did this job myself, 5...10 maybe? I'm a coffee roaster, not a Q-grader. I leave that job to the people that are paid to do it. Their job is to find the bad stuff in a crop and filter it out. Then I get to cull the best of that lot for myself. My job is to take those coffees and discover the best they can be. They are two very different tasks. Sure, I pay a bit more for the service, but it is money well spent, IMO.

Unfortunately, because they are importers, not roasters, when I have attending cuppings, I find many more roasting defects than green defects. It is tricky to weed through them and pick out a coffee that I know has potential.

That said, I think I will take the Q course soon. I'm still not interested in traipsing around the jungles of central America, but it does offer a basis for the language of coffee.

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luca
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#7: Post by luca » Sep 02, 2019, 9:30 am

RapidCoffee wrote:Great post, Luca! I wish there were similar coffee tasting/rating opportunities available in my area.
Hmm ... well I may have some mouldy green around I could send you! I think that these are quite valuable to do and re-do. Tasting purposefully created roast defects is a really interesting exercise, too.
Almico wrote:That's oh so true. Many an overblown coffee ego gets deflated over a cupping table with people that really know what they are doing.
Totally. I think it's quite important to set up cuppings with somethings that are falsifiable to give you some confidence that you've figured it out. So one thing that I like to do is to repeat one or two of the coffees in a flight, though I've usually got too many samples around and often don't get to do it. With single blind cupping, there's always the game of trying to guess what is what, which is not really something that you can expect people to do if they aren't familiar with the coffees. Still, I started a coffee cupping group this year and I have been delighted to see that in the space of just a few structured cuppings, people have gone from being relatively new to now routinely getting single blind guesses right on tables of similar coffees. I also often put things into lineups that I know or suspect will be bad, just to have good reference points, and I was staggered earlier this year to taste an under-roasted coffee that came quite good when it sat for long enough that I would have thought that it would have gone stale. That caused me to pull myself up on how long I was allowing coffee to rest, and I've seen some good improvements on some roasts because of it. So I definitely think there's tonnes to learn if you (a) cup blind, (b) cup with others, (c) cup large enough lineups to make good comparisons, (d) keep an open mind and (e) put to the test things that you think you already know.
Almico wrote:I get asked all the time if I have ever been to origin, as if that is some right of passage for a coffee roaster. OK, it might be fun to visit, but as a process of selecting coffees to offer at my bar, no thank you. That ordeal is much better left to Q-graders that do it for a living.

I use 3-4 importers for my coffee. All my reps are Q-graders. I am not. They spend months during any given year in the fields selecting coffees and bringing home the best of their efforts. How many coffee farms would I get to visit if I did this job myself, 5...10 maybe? I'm a coffee roaster, not a Q-grader. I leave that job to the people that are paid to do it. Their job is to find the bad stuff in a crop and filter it out. Then I get to cull the best of that lot for myself. My job is to take those coffees and discover the best they can be. They are two very different tasks. Sure, I pay a bit more for the service, but it is money well spent, IMO.
Perfectly sensible approach. I haven't done buying, but I gather that there are pretty compelling economies of scale in hitting a full shipping container load from one port. If you're not a fairly large roasting operation and you're going to offer coffees from a few different origins, then all of a sudden that's a lot of coffee to be moving around and a lot of time that needs to be spent, not only on the buying, but also on the logistics. Then on top of that, you've probably got a lot of risk tied up in what you have bought; eg. if you've only bought a few things from one origin and they turn out to be duds, then you've got problems ... I mean, even if you can get your money back, you've still got to organise replacement coffee. Forecasting your consumption rates also doesn't seem easy, so you're probably going to end up buying some stuff spot anyway. The extra money on buying spot isn't just buying their cupping services, it's also minimising your risk and avoiding high fixed costs. There's certainly lots of very good coffee to be had from importers, and even fairly large specialty coffee roasters dip into the spot market.
Almico wrote:Unfortunately, because they are importers, not roasters, when I have attending cuppings, I find many more roasting defects than green defects. It is tricky to weed through them and pick out a coffee that I know has potential.

That said, I think I will take the Q course soon. I'm still not interested in traipsing around the jungles of central America, but it does offer a basis for the language of coffee.
Yeah, I think the Q is a fantastic experience. I gather the pass rate for first timers isn't high, but that's not really the point. I suspect that if you've at least done the course, it will hopefully make it harder for your reps to dismiss your complaints if you ever were unhappy with something that you bought. Importers are great at finding a buyer who will be happy with every coffee that they have to sell, even coffees that have problems with them; if you can make sure you're speaking the same language that they are, then it lessens the chance of them directing the wrong coffees your way, too.

The roast thing is irritating to hear. Are they good about sending green samples, at least? I guess the problem is that then you've got to have a reliable way to roast them!
LMWDP #034 | 2011: Q Grader Exam, Brewer's Cup #3, Australian Cup Tasting #1

EddyQ

#8: Post by EddyQ » Sep 03, 2019, 12:23 am

I really wish green bean suppliers would offer green beans with known defects. I'd buy them just to experience them in the cup once in a while to sharpen my palate.
As a home roaster, I buy greens though small qty supplies who I trust (similar to almico). I use to cup and pull espressos with each roast. But the cuppings rarely resulted in any findings. Likely because there was no green defects. But my espressos, I found many flaws with my roasts and the quality of the greens.