Green bean grading is the process of categorizing the chosen coffee beans on criteria such as size, the altitude where it was grown, preparation methods and the cup quality. The color of the bean tells us about how the coffee has been treated. A green jade color is ideal, however seldom obtained. A faded green to gray color means that deterioration occurred during shipment. A gray to white color shows serious quality decrease, due to over-heating or prolonged storage.
- Overripe beans/floaters: in the wet processing they float and are skimmed off the water’s surface - Underdeveloped/‘Sour bean’: detected visually by an off color and very wrinkled surface - Black bean/Stinker: a coffee bean that fully rotted in the fruit.
Coffees are also graded by the number of imperfections such as defective and broken beans, pebbles, sticks, unripe beans and or black beans, per sample. The ultimate guide to a coffee is always its cupping profile, even if the beans look irregular, as this might be a characteristic of a coffee giving it a special taste. Below are some of the most common defects found in coffee.
- Partial Black: similar to a fully black bean, the coffee bean partially rotted in the fruit. - Insect damage - Broken - Beans Malformed.