Hello all,

It's common to see someone post a graph and say that they were unhappy with it. The biggest problem here, is people leave out TASTE!

Lets start here with some flavors. I suggest that you cup and taste taste every roast objectively and try to put to words what it is that you are tasting. Taste blind too.

Here is a the SCAA flavor wheel that can help. Start in the middle and work you way outwards to try to pin down what your tasting. There are other flavors of course but this is a start.

http://www.scaa.org/chronicle/wp-conten ... .18.15.jpg

Here is a link for the SCAA cupping guide lines. Its really easy once you get it figured out.
http://www.scaa.org/?page=resources&d=cupping-protocols

BAKED

Baked flavors are generally described as: Paper, Cardboard, Straw, Woody, Flat, Dull.

Possible solutions are:
-Try to steepen the angle of you ROR curve. Try not to have your ROR flat line.
-I get this flavor in old stale dry coffees too. Use fresh green coffee
-Here is a thread I found about Baked as well
http://forums.roastersguild.org/viewtopic.php?t=179

GRASSY/VEGITAL

These flavors usually come from underdeveloped centers.

Possible solutions are:
-Have sufficient energy at the beginning of the roast. Especially with dense coffee.
-Make sure you develop sufficiently after first crack starts.
-after your roast has cooled, crack a few beans in your hand and look for color evenness throughout. If the center is obviously lighter then you know.
Here is a thread
Light roast, grassy flavour!?
here is a blog by Matt Perger
https://baristahustle.com/blogs/barista ... and-colour

CHAR/BURNT

Flavors of Charcoal, Tar, Ash, Burnt, Acrid, Starbucks

-Obviously in darker roasting (FC+ and French) some of these flavors are sometimes preferred. However, I find in a good dark roast these flavors are complimented with a rustic sweetness.
-Charging too hot, creating tipping and scorching.
-Drum speed to low causing facing and scorching
-Too high temps, during roast, or too far after firstcrack

Here are some pictures
https://coffeecourses.com/coffee-roasti ... es-photos/

Smoky

Smoky smell, and taste in coffee (some smoky flavors are acceptable in darker roasts.)

-Not enough airflow to pull the smoke off the beans
-Clean the roaster, built up chaff and coffee can be burning in other places adding smoke

Overly Sour/Acidic

flavors of pure Lemon juice, acid, puckering, under ripe fruit, unpleasant.

Acid can be a desirable flavor in coffee. It livens up the cup and contributes to fruit flavors, but it should not be so acidic that it is unpleasant. African coffees such as Kenyan, are known for being higher acid coffees.

-Extremely under developed roast. Make sure you roast long enough after first crack starts.
-Make sure you give enough energy in the beginning of the roast.
-Roast a bit darker.
-make sure your brewing method is sound. Good coffee, brewed poorly can be overly acidic.

Matt pergers brewing compass
https://baristahustle.com/blogs/barista ... ee-compass

Dry/astringent

Flavors like sucking on a tea bag, mouth drying, bitter

Possible cause is too much air flow. Try lowering airflow.


Anyways, I do not know everything. A lot of coffee is subjective. This is just from my own experience and internet research. I am very much open to other peoples experience, and tips. Heck I might even be wrong on things. Id like to continue adding to this thread.

~Adam

As far as overly acidic coffees go, I'd recommend not necessarily going with more heat in the beginning but possibly going for a higher charge temp but lower heat application throughout. A higher charge temp will keep that inner/outer differential high and will allow you to use less heat in the drying phase of the roast.

While using less heat in the drying phase of the roast won't necessarily have any affect on the flavor of the coffee, it will cause you to go into first crack with less momentum, thereby extending your time in first crack. Longer time after first crack can increase the sweetness of coffee while similaneously causing your eye puckering acidity to be mellowed out into a meyer lemon (as an example). You will still have all the sweetness as long as you stay closer to first crack.

Caramels develop by temp after first crack, acidities by time after first crack. Just make sure your charge temp isn't so high that you begin to cause tipping in the coffee.

Just something I've found through my own personal experience

Excellent post Adam!

Look forward to hearing more opinions on how to manage roasting defects and improve outcomes.

Great guideline post, Adam!

Perhaps i could offer a few personal experiences with regards to baked coffee. If cupping it while hot, it can be easy to mistake it for a light roast. After the cup cools, usually at around the 20 minute mark it becomes flat. You'll notice some flavour upon slurping and then it immediately falls off, no finish or aftertaste to speak of. Roast profile wise, it can come from a coffee being roasted for too long without ever reaching a defined first crack (low RoR for extended time).

Nice, quick guide. This is essentially the focus of the Rob Hoos book, Modulating the Flavor Profile of Coffee. In that book he's not just steering away from "off" flavors, of course.

marista wrote:Great guideline post, Adam!

Perhaps i could offer a few personal experiences with regards to baked coffee. If cupping it while hot, it can be easy to mistake it for a light roast. After the cup cools, usually at around the 20 minute mark it becomes flat. You'll notice some flavour upon slurping and then it immediately falls off, no finish or aftertaste to speak of. Roast profile wise, it can come from a coffee being roasted for too long without ever reaching a defined first crack (low RoR for extended time).

What level is too low for RoR? Something I've noticed with my quest is I'll enter first crack at 13-16F ROR and it still never "rolls" or really gets cracking like it would on my huky. Why do you think that is?

Thanks for taking the time to create this, it's a good quick reference.

I too was guilty of stressing over Artisan graph interpretation for a long while, but have since relied more heavily on cupping to guide my roasting.

@dale_cooper Joe, i've found that to be dependent on both the coffee and roasting machine, as well as batch size.
with a larger batch size you would have more momentum and in the case of the quest m3 (which is very conductive by nature), you do have much more bean-to-bean surface conduction of heat with a larger batch size than you would with a small batch.

coffee wise, i do note that kenyan and ethiopian coffees like a higher RoR during development. kenyan coffees are pickier from my experience. too low a RoR and you get the bean surface darkening too much and creating some roasty flavours even though the inside is correctly cooked, too high a RoR and you get a nice light surface but underdeveloped inside. ethiopian coffees seem more straightforward in this regard, too low a RoR and its just plain underdeveloped and dark outer bean colour. colombian coffees like a slightly lower RoR than the african coffees, rwandan coffees as well but be careful to control the final out temperature because they tend to darken much quicker than most other origins.

all these are based on my observations though, so YMMV. would be happy to know anything else you've observed! (: