Bean Defects

Damage from the Antestia bug, resulting in coffee beans ranging from slightly discolored to almost entirely black and shriveled up.  

Pieces of coffee beans crushed during processing.  

Black, or very dark, unroasted beans. Black beans typically result from harvesting immature cherries or by harvesting dead cherries that fall naturally from the tree. Black beans can also result from exposure to water and heat and insect-damage. Unroasted coffee beans with more than 25% black, deep blue, or dark brown surface area, may be considered black beans. Black beans have a detrimental effect on coffee taste. The number of black beans in a representative sample is a basic measure of coffee grade.  

Irregular greenish, whitish or yellowish patches on unroasted coffee beans. Blotchy beans may result from incomplete or uneven drying during processing.  

Beans with ends that curve upwards like a boat.  

An extra large coffee bean. Sometimes a peaberry which has not totally grown together.   

Coffee Berry Borer damaged coffee beans. The Coffee Berry Borer, or Hypthenemus Hampei, is one of the most significant pest problems for coffee farmers. The CBB is a black, two millimeter long, beetle that bores holes through the seeds coffee cherries. "Broca" is the widely used Spanish term for the coffee berry borer. CBB damage is also called "Broca damage".  

Crushed coffee beans are most commonly the result of improperly set or damaged pulping equipment. Coffee beans can also be crushed during mechanical separation of the beans from the husk, or during mixing in fermentation tanks.   

Disease damaged coffee beans. There are many coffee plant diseases that can damage a coffee crop, but most are caused by fungus (mold). The most prevalent coffee mold problems are Coffee Leaf Rust (CLR), which shows as yellow-orange blotches on the leaf, and Coffee Berry Disease (CBD), which lives in the bark of the tree and produces spores that attack the coffee cherries. CLR, CBD, and Coffee Berry Borer (CBB) are significant disease and pest problems facing the worlds coffee farmers.  

Ragged shaped, pale, and light weight unroasted coffee beans. Also called "droughty", or "flaky"  

An cluster of two or more deformed beans that grew closely locked together, but sometimes separate during processing or roasting. Also called "ears", due to their often ear-like appearance.  

Unroasted coffee beans that have lost much of their original color, a characteristic of old crop and beans that were dried too rapidly. Processed coffee beans will slowly fade from green to pale yellow, if stored too long before roasting. Also called "soapy" or "bleached".   

Unroasted coffee beans with a brown or rust color. Foxy beans may result from faulty fermentation, improper washing, over drying, or by harvesting over-ripe cherries. Also called "brown".  

Unroasted coffee beans with a light green or white fur-like texture characteristic of mold. Roasted coffee beans affected by mold have a "musty", or "moldy", flavor.  

Unroasted coffee beans with blotchy discolorations, associated with uneven drying during processing.  

Taste or aroma characteristic of mold. A musty characteristic is associated with drying the coffee too slow or storing unroasted coffee in a damp environment. Monsooned and aged coffees may have a slightly musty flavor.  

Coffee allowed to ferment too long during wet processing. After de-pulping coffee cherries to remove the skin and some of the pulp, the separated seed will still have a significant amount of pulp attached. The remaining pulp can be loosened by fermentation, allowing it to be washed away before drying. If fermentation is not stopped as soon as the remaining parchment is no longer slimy, and has a rough texture, the coffee may acquire oniony or soury flavors.  

Unroasted yellow coffee beans that stink when crushed or ground. Pales may result from drought or from harvesting immature coffee cherries.  

A single rounded bean from a coffee cherry which bears one bean instead of the usual flat sided pair of beans. Also known as 'caracol', 'perla' and 'perle'. Peaberries are frequently separated and sold as a distinct variety. Papua New Guinea and Tanzanian peaberries are good examples.  

Wet processed beans that are cut or bruised during pulping. Typically caused by damaged or improperly configured pulping equipment. Pulper cut beans will usually show brown or black marks after processing. Discoloration develops by oxidation at the damaged areas and off-flavors may result. Pulper damaged beans roast unevenly, age rapidly, and are susceptible to damage by vapors, dust, and other adverse environments. Also called "blackish" or "pulper cut".  

Unripened coffee beans, often with a wrinkled surface. Quakers do not darken well when roasted.  

Coffee with a ragged appearance. Harvesting both mature and immature cherries, or drought-affected cherries, can result in beans with a ragged appearance.  

A common defect where coffee beans have a large cavity similar to a shell. While only a secondary concern, compared to defects such as stones, sticks, black beans, or sour beans, too many shells in a coffee sample is an indication of a lesser coffee grade.  

A coffee bean that produce an unpleasant or fowl taste. Beans that get stuck in a pulper or fermentation tank too long are may become stinkers. Stinker beans produce an unpleasant smell when crushed or cut. Stinker beans can spoil the taste of an otherwise good batch of coffee.  

Beans with a moisture content above 12%. The final drying process should result in coffee beans with a 10% to 12% moisture content.  

Wrinkled, undeveloped, and light weight coffee beans. Withered beans are typically the result of drought or poor husbandry.