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 it resembles a cherry, starts to ripen for picking. Each tree, hand-picked several times between August and January, provides around 15 pounds of cherry, which results 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 placed overnight in a fermentation tank. The fermentation time is about 12 hours at low elevations or 24 at higher elevations. 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 the 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: 9.0–12.0%). Too much moisture 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 before roasting or wholesale. Kona coffee beans are classified by law 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, and purity of bean type. Type I Kona coffee grades are 'Kona Extra Fancy,' 'Kona Fancy,' 'Kona Number 1', 'Kona Select,' and 'Kona Prime.' Type II Kona coffee grades are 'Peaberry Number 1' and 'Peaberry Prime.' Also, a lower grade of coffee, called 'Number 3' (or 'Triple X'), can not legally be labeled as "Kona" but as 'Hawaiian' coffee. Any bean grade below Number 3 is considered 'Offgrade' coffee and can only be labeled generic. Not an official classification grade, but commonly used by Kona coffee farmers, is the 'Estate' grade, which consists of various separate grades except for removing the 'Number 3' and 'Offgrade' beans. 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 resistant to the nematodes. It could be grafted with
Coffea arabica 'Guatemala' variety to produce a plant that naturally resists the pest, still producing 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. ==Kona blends==