What are black beans in coffee processing?
Black beans are a defect in coffee that occur when the interior of the coffee bean, or endosperm, is completely black due to fungal, mould, yeast, or pest infestations. This typically happens when the coffee cherry is over-mature and falls to the ground, where it is more susceptible to attack. One common culprit is the Colletotrichum coffeanum fungus, which can lead to a total discolouration of the endosperm. Other causes of black beans include overfermentation of mature cherries, which can result in mould and yeast infestations.
Black beans are a major issue in the coffee industry, as they significantly lower the quality of the coffee and can render it unsellable. In coffee grading, full black beans are the worst type of defect and score 1 full defect point.
When it comes to roasting, black beans are particularly problematic, as they resist roasting and have a very harsh, acrid flavor. This can lead to off-flavors and a burnt taste in the final cup of coffee.
To prevent black beans from occurring, it is important for coffee farmers to properly manage their crops and harvest them at the right time. This includes using proper pruning techniques to ensure that the cherries are not overripe when harvested, as well as implementing effective pest and disease management strategies.
In summary, black beans in coffee cultivation and processing are a major issue that significantly lower the quality of the coffee and can render it unsellable. Preventing their occurrence requires proper crop management and effective pest and disease management strategies.