After Coffee Cherries are Picked
Within 24 hours, fresh cherries from the Kona slopes are run through a pulper that removes the juicy outer flesh and separates the beans from the pulp. These pulpers use rough rollers that break up and loosen the outer skin of the cherry and remove the mucilage surrounding the coffee bean. The beans are rinsed in clean water.
Time in the Fermentation Tanks
After the coffee beans are pulped, they are carefully fermented in a fermentation tank. This wet-method of processing is said to contain the secret to the bright, clear flavor of Kona Coffee.
Length of time in the fermentation tanks depends on the temperature and elevation of the tanks. At lower elevations, it usually takes 12 hours. At higher elevations, the process can take up to 24 hours in the tank. Fermentation is a key process that prevents the cherries from fermenting on their own, which brings out strong unpleasant flavors and can contaminate an entire batch.
Drying in the Hawaiian Sun
After fermentation, the coffee beans are rinsed again in clean water and laid out on a flat surface to dry in the sun and the warm Kona breezes. The platforms are called hoshidanas – traditional hoshidanas have rolling roofs so the premium Kona coffee beans can be exposed to the sun during the heat of the day and then covered when it begins to rain in the afternoon. At regular intervals, the beans are raked with a wooden rake so they dry evenly.
Natural drying takes about 1-2 weeks.
After the beans are dry, they are milled to remove the stiff, paper-thin, white membrane called parchment. Hullers are used to remove the parchment and polish the Kona coffee bean.
Sorting and Classification
After milling, the Kona coffee beans are sorted and graded to meet State of Hawaii Department of Agriculture Standards. The process involves separating the coffee beans by size and shape. A vibrating air table employs gravity to separate and grade the beans by density and also get rid of defective beans.