Prospective reading on coffeed.com
The two least favorite chemicals in coffee according to this blog: 2,4,6 trichloroanisole(TCA) and Geosmin
Two sources of your earthy musty, moudly, dirty smells/flavors in coffee. Charming, I think not. In wine, you can find mention of these flavors with cork taint, poor handliing of the grapes and other general missteps in the processing of wine. TCl and Geosmin are also noted in wine as being associated with barnyard (something so unhygenic in preparation that it took all the unsavory substances of a barnyard to create) flavors but sometimes in coffee, many pundits call these wild and intriguing.
Earthy alone is such a strange descriptor in coffee. In wine, earthy is often frowned upon by many as an imperfection. To quote an article on winepages.com on Earthy: 'It is not a "goût de terroir", which in its true sense means expressive of its terroir or complete growing environment, not tasting simplistically of earth!' Yet, there are many who desire this character in coffees and in particular in espresso. Simply put, this is an old way of thinking that goes back into the use of Robusta and dark roasts for espresso because of some perception of what espresso should be....
One of my favorite espresso is the nontraditional Ecco Reserve, a blend of two brazils(Cachoeira & Daterra farms) offered by Andrew Barnett of Ecco Caffe. I would not use earthy as a descriptor in this coffee but it is a fabulous espresso on it's own. I wouldn't use that to define any of the drip coffees from Terroir either. In some ways, the more expenisve coffes coming out of CoE present this profile of clarity and cleanliness over earthy muddled flavors.
It seems in many ways clarity is the antihesis of earthy. Yet, earthy is so tied to 'body' and our perception of the generic espresso profile. This leads me to consider that flawless coffees may be lacking or of less body than muddied defect laden coffees. I wonder in essence if we should continue to grade body as often as we do in any way as an indicator of quality? The funny thing is that once you are weened off of the earthy profiles, it's a brick to the teeth to try and go back.
One of the more pleasurable finds was a chemical named β-damascenone. Noted for it's aroma of honey, roses, and exotic flowers. This is an actual component of rose aroma, teas, and evidently many different products such as red wines. The other intruiging notes are on Furals, furans, and some aldehydes which seem to lead to a lot of the ideal fruity and floral but volatile and fleeting aromas I enjoy, but that's another entirely more complicated post. So the next time someone drops a floral or perfume remark, you can say, yep, that's posible. There are more than enough chemicals in coffee for us to compare coffee to wine complexities and intricate floral aromas.
The point of this is that coffee has the same potential as wine to be a culinary experience. We just have to get the right green, the right roast, and the right extraction to make it all come together in that defining moment on the cafe floor. As I see more and more defining experiences among all the boring ones out there, I feel a change coming in the industry abut how people perceive coffee.
The flavors are all there to be had and we just discover how to get at them and repeat them. A mouthwatering task, but that's the best part... we get to taste everything.
-Jaime van Schyndel
See also “…Coffee: The Chemistry behind its Magic” by Marino Petracco