Years ago, in another phase of my life, I was involved in the Kona coffee business. I traveled to the Big Island of Hawaii, stayed at a coffee farm up high on the mountainside on the famed Kona Coast area, and learned a lot about how coffee is grown, processed and roasted. So I thought I would share some of that information here with my fellow foodies.
The Kona coffee industry goes back well over 100 years. When Mark Twain visited Hawaii in 1866, he waxed enthusiastic about it, saying "Kona coffee has a richer flavor than any other, be it grown where it may and call it by what name you please." Many connoisseurs would agree with him. To this day, Kona coffee is considered one of the world's most prized coffees, in the same league as the famed Jamaica Blue Mountain coffee.
Although coffee trees were originally brought to Hawaii from Brazil, they were from a strain of Coffee Arabica trees that originated in Ethiopia. The volcanic soils and relatively moderate temperatures on the higher slopes on the Kona coast turned out to be ideal for the cultivation of coffee. However, the terrain is not suited to mechanical means of production, and to this day Kona coffee must be picked by hand.
The steps in processing Kona coffee are also very labor intensive. First, the red coffee berries (called "cherry") are packed into 100-lb burlap bags for handling. The cherry is then processed through a machine called a "pulper", which removes the bright red berry and leaves the seeds, which are the actual coffee beans. Usually there are two seeds per berry; but sometimes, the seeds do not separate and remain one round seed. These, when processed and packed, are known as "peaberry". Oddly, the round peaberries are smaller than their single counterparts.
The freshly-pulped seeds are then soaked for 18 to 24 hours or so in a tank of water. This process allows fermentation that processes the sugars on the outside coating of the beans, preventing later spoilage.
Next the beans are put out on wooden decks to be sun-dried. Even though the Kona coast is relatively dry, by Hawaiian standards, still they get their share of rain. So the drying decks have roofs that can be pulled over the beans when the rain comes. During the drying process, the beans are raked from time to time with large wooden rakes to keep turning them and allow them to dry evenly. When dry, the outer coats, called "parchment", have a very light color, something between sand and eggshell.
Once the beans are dry enough, they are again packed into burlap bags and taken to the mill. At the mill, machines separate the beans by size and remove the parchment to produce the green coffee beans ready for roasting. For longer term storage, beans will usually be kept in the parchment and not milled until they are ready to be shipped to the roaster.
Roasting is an art in itself. There are points at which the beans make a "cracking" noise, and experienced roasters know exactly what to look for, listen for, and smell to determine when they have achieved the desired level of roasting. The usual roasting levels that people talk about are light, medium and dark; the dark roast will result in the bean releasing its oils to some extent, and therefore these should be used soon after roasting.
The differences in coffee flavors from different regions of the world are due to many factors: the plant stock (all gourmet coffees come from varieties of the "arabica" family rather than the "robusta" family of coffee trees), climate and soil, farming methods, how and when it is picked (Kona coffees are picked by hand, and during the harvest season, there will be several passes because the pickers will only pick the ripest red coffee cherries), and how it is processed. Both Kona and Jamaican coffees are processed similarly, resulting in clean light coffee flavors. African coffees typically are dried in the cherry before the beans are removed; this results in a different sort of flavor that many people find to be richer and more complex than Kona, Jamaican or the typical Central American coffees.
In my own view, Kona coffee is deserving of its special status among the world's coffees. It has a wonderfully floral aroma, and a rich yet mild flavor without any bitterness. What it lacks in complexity it more than makes up for with its purity of coffee flavor. I prefer my Kona coffee roasted at a medium level rather than dark, because the darker roast tends to overpower the subtleties of its flavors.
Oh, one more thing. If you would like to try some great Kona coffee from family farms and at quite reasonable prices, I recommend the following two sources. Please note, I am not affiliated in any way with these two family farms, but I am acquainted with them and know how they grow and process their coffee. It is top notch.
Kona Purple Mountain (I recommend the Full City Roast)