We’ve mentioned a thousand times the importance of coffee cupping for roasting a quality cup of coffee. No matter how meticulous you are with your roasting, nothing can replace getting in there and tasting the roast to determine if changes need to be made in the roasting. Cupping also serves as an important tool to identify defects that are a result of nature or through the processing of coffee through the supply chain. As a roaster, you hear about many of these defects but you don’t really know what they are until you experience them. Here are six big flavor notes that are a red flag for defects:

Musty/Earthy: These beans are moldy. Coffee seeds are porous so if they aren’t dried properly or with good air flow, they can pick up some of the earthy flavors around them (i.e. the ground). If there’s a lot of moisture or heat in the area, then the beans can pick up the moldiness.

Fermented: You’ll experience tasting notes of rotten fruit or vinegar. When you take the mucilage off the coffee seed, you use the fermentation process to remove the mucilage. If you over-ferment, then that can carry those flavors on to the seed. Another time you’ll see this happen is when the processing equipment isn’t cleaned very well, some old and super-fermented beans can get mixed in with the new batch.

Unripe: This one is pretty self-explanatory, but if coffee cherries are picked while unripe, the resulting coffee can taste green, grassy, and astringent.

Rioy: Usually in natural processed arabica coffees grown in Brazil and shipping through Rio. The resulting coffee smells like a bandage (gross!) and has iodine notes. They aren’t sure why this happens, but a fungus is suspected. People that like Turkish coffees tend to like this attribute in their coffees.

Phenolic: Tasting notes are medicinal and iodine. This defect is tricky. Sometimes it’s known in certain areas (i.e. Colombia) but it’s unknown why some of the flavors come through. It’s linked to a certain type of mold.

Faded/baggy: Tasting notes include wood, paper, and cardboard. If a coffee is past crop or getting too old before roasting these are common tasting notes. It is also a result of poor storage.

To avoid most of these defects, farmers should avoid picking cherries off the ground or picking unripe cherries. In processing, they should carefully sort coffee cherries using good clean water and be sure to ferment properly with appropriate duration unique to area and be sure that whole process is sanitary. See more on common coffee roasting defects with our previous blog article.