While the quality of the bean is established by the growing environment (climate, altitude, soil type, variety and agronomic practices), the level of these chemicals is reduced during processing, particularly if fermentation is poor.
It is generally accepted that the wet process produces a better, more flavorsome, fruity coffee as a result of the fermentation and drying process. Under-ripe, overripe, damaged and diseased cherries will all adversely affect the quality of the chemical constituents of coffee.
The end consumer wants a consistent, clean cup. Different countries have different tastes and requirements. The quality of green bean coffee is determined by its physical appearance, then when roasted by its fragrance and finally by specialists tasters who assess and score its
flavor, aroma and body. In general, Arabica coffee has better “cup quality” than Robusta coffee.
Potassium has a crucial role to play in mobilizing coffee berry quality through its role in the movement of sugars from the leaf for accumulation in the fruit. The nutrient has a direct effect on processed coffee quality. Increasing potassium use to the optimum amount of 200 kg/ha in trials improved the polyphenol oxidase activity, color index and sugar content, which are directly related to the cup quality of coffee.
In the same trials, the most efficient form of potassium was potassium nitrate. In order to reach optimum coffee cup quality, less potassium nitrate was needed in comparison with potassium applied as potassium sulfate and potassium chloride.
Calcium is important for strong cell wall formation which has a major effect in maintaining fruit quality and thereby coffee cup quality. Even though less than 15 % of the total coffee tree calcium is found in the fruit, this low concentration is critical for berry quality. Trials conducted by Cenicafe indicate that applying Nitrabor can help improve the overall quality of coffee. It is known that calcium and boron work together in the formation of strong cell walls.