Growing and Processing
A coffee orchard requires 3 - 4 years of maintenance before a significant crop can be harvested. Kona coffee blooms in February and March. Small white flowers cover the tree and are known as Kona Snow. In April, green berries begin to appear on the trees. By late August a red fruit, called "cherry" because of the resemblance to the fruit, start to ripen for picking. Each tree will be hand-picked several times between August and January, providing approximately 20-30 lbs of cherry.
Within 24 hours of picking, the cherry is run through a pulper, the beans are separated from the pulp and then placed in a fermentation tank overnight. The fermentation time is dependent upon the temperature and, therefore, on the elevation; about 12 hours at a low elevation or 24 hours 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 the event of rain. It takes 7–14 days to dry the beans to an optimal moisture level of between 10-13% (per Hawaii Department of Agriculture regulations: 9.5-12.5%). 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 the seed type:
- Type I beans consists 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 a peaberry.
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
- Kona Prime
The grades of Type II Kona coffee are:
- Peaberry Number 1
- Peaberry Prime
It takes 4.25 lbs of coffee cherry to produce 1 lb of dried parchment.
- Each day’s harvest must be processed that day to ensure the highest quality in the final product.
- Coffee cherry is delivered to a facility called a pulping mill. Here, the under ripened and over-ripened cherries are discarded and the pulp from each remaining coffee cherry is then removed.
- Each coffee cherry contains two separate coffee beans. After pulping, these beans are referred to as wet parchment.
- The wet parchment is then held in a fermentation tank for 12 - 14 hours. The fermentation is required to break down a mucilage layer on the outer surface of the parchment.
- After fermentation, the parchment is washed then dried.
- Dried parchment is delivered to the Dry Mill where the parchment skin is removed by a gentle hulling process.
- Dried parchment is then reposed (allowed to rest) for at least 30 days to allow the moisture to equalize within each bean. This helps to ensure an “even” roast.
- It takes 1.25 lbs of dried parchment to produce 1 lb of green bean coffee.
- ￼The coffee beans, now referred to as green bean, are then separated into categories of bean size. Using an Oliver gravity table, they are then graded according to density. This ensures that only the perfectly formed beans are bagged and certified. This process is called “grading the coffee” and is dictated by a strict set of guidelines administered by the Hawaii State Department of Agriculture.
Challenges Faced by Kona Coffee Farmers - Past and Present
Infestations of the root-knot nematode damaged many trees in the Kona districts in the 1990s. Symptoms of this type of damage are single or clusters of trees with stunted growth, particularly 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 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 1970s.
Current day, the Coffee Borer Beetle is threatening Kona coffee crops. The beetle bores into the coffee berry to lay its eggs. The larvae feed on the coffee bean, reducing the yield and quality of the bean. Because the larvae are inside the bean, it makes it difficult to control with pesticides. In ideal conditions (which appear to be very much temperature dependant) a single beetle can breed up to 4 or 5 new generations, in a single year: and with (a very conservative) 50 eggs per female, per laying; it will not take long for them to become a serious, and major pest, to coffee.