Kona Coffee - Growing and Processing

Growing and Processing

Kona coffee blooms in February and March. Small white flowers known as "Kona snow" cover the tree. Green berries appear in April. By late August, red fruit, called "cherry" because of resemblance to a cherry, start to ripen for picking. Each tree, hand-picked several times between August and January, provides around 15 pounds of cherry, which result in about two pounds of roasted coffee.

Within 24 hours of picking, the cherry is run through a pulper, the beans are separated from the pulp, and then placed overnight in a fermentation tank. The fermentation time is about 12 hours at a low elevation or 24 at a higher elevation. The beans are rinsed and spread to dry on a hoshidana or drying rack. Traditional hoshidanas have a rolling roof to cover the beans in rain. It takes seven to 14 days to dry beans to an optimal moisture level of between 10 and 13% (by Hawaii Department of Agriculture regulations: 9.5-12.5%). Too much moisture content in coffee allows the growth of ochratoxin A, a harmful mycotoxin, hazardous to human health. From here, the beans are stored as "pergamino" or parchment. The parchment is milled off the green bean prior to roasting or wholesale.

Kona coffee beans are classified according to seed. Type I beans consist of two beans per cherry, flat on one side, oval on the other. Type II beans consist of one round bean per cherry, otherwise known as peaberries. Further grading of these two types of beans depends on size, moisture content, purity of bean type, and size. The grades of type I Kona coffee are 'Kona Extra Fancy', 'Kona Fancy', 'Kona Number 1', 'Kona Select', and 'Kona Prime'. The grades of type II Kona coffee are 'Peaberry Number 1' and 'Peaberry Prime'. Also, a lower grade of coffee, called 'Number 3' can not legally be labeled as "Kona".

Infestations of the root-knot nematode damaged many trees in the Kona districts in the 1990s. Symptoms are single or clusters of trees with stunted growth, especially when transplanted. In 2001, rootstock from the Coffea liberica species was found to be resistant to the nematodes. It could be grafted with Coffea arabica 'Guatemala' variety to produce a plant that naturally resists the pest, as well as produces a quality coffee product. The combination was named after Edward T. Fukunaga (1910–1984), who was superintendent of the University of Hawaii's Kona Research Station in Kainaliu in the 1950s through the 1970s.