A coffee defect is an unpleasant (negative), irregular coffee flavor characteristics/taste sensations due to careless processing of the green coffee beans, improper harvesting, improper moisture content during storing, or any other bean property including physical defects that causes a flavor and/or aroma defect/fault/taint.
A Compendium of Potential Coffee Bean Defects
Some flavor/aroma defects/faults/taints include acerbic, acrid, baked, baggy, brackish, bready, caustic, earthiness, fermented, foreign, gaminess, grassy, harshness, hidey, hospital, insipid, medicinal, moldy, musty, new crop, oniony, past crop, peasy, potato, quakery, rancid, rioy, rotten, rubbery, scorched, sour, stale, strawy, tarry, tipped, unbalanced, vapid, and wild.
Effects of Coffee Bean Defects
Flavor and aroma defects/faults/taints may be irritating, sharp, extremely bitter, or otherwise foul tasting. Some of these tastes may be desirable to some degree by some people, since coffee taste preferences are extremely subjective.
Physical Coffee Bean Defects
Green coffee beans can also contain physical defects and imperfections such as
- chipped or beans
- underripe beans
- overripe beans
- black / rotten / moldy beans or quakers
- infested or eaten by insects and pests
Physical defects should be sorted during the processing stage and sorted by the growing cooperatives or brokers within the originating country. A good coffee broker will represent a roasters' best interests by examining green coffee lots that arrive and paying appropriately for lower grades.