Kona Coffee Drying Process
The Kona coffee cherries are spread out in the sun, either on large concrete or brick patios or on matting raised to waist height on trestles. As the cherries dry, they are raked or turned by hand to ensure even drying and prevent mildew. It may take up to 4 weeks before the cherries are dried to the optimum moisture content, depending on the weather conditions. On larger Kona Coffee plantations, machine-drying is sometimes used to speed up the process after the coffee has been pre-dried in the sun for a few days.
The drying operation is the most important stage of the process, since it affects the final quality of the green coffee. A Kona coffee that has been over dried will become brittle and produce too many broken beans during hulling (broken or pieces are considered defective). Coffee that has not been dried sufficiently will be too moist and prone to rapid deterioration caused by the attack of fungi and bacteria.
The other dried cherries are stored in bulk in special silos until they are sent to the mill where hulling, sorting, grading and bagging take place. All the outer layers of the dried cherry are removed in one step by the hulling machine.
The dry method is used for about 90% of the Arabica coffee produced in Brazil, most of the coffees produced in Ethiopia, Haiti and Paraguay, as well as for some Arabicas produced in India and Ecuador. Almost all Robustas are processed by this method. It is not practical in very rainy regions, where the humidity of the atmosphere is too high or where it rains frequently during harvesting.
Roasting Kona Coffee On The Farm
Coffee roasting is a centuries-old craft that requires years of dedication to perfect. The best roasters know that a split second can be the difference between superb flavor and a wasted effort.
Choose The Roasting Process from the menu at left and follow the roaster through the steps of a perfect roast–you’ll see why roasting coffee is equal parts art and labor. Or select European Dark Roasts to learn what’s made these classic roasts favorites for over a century.
Techniques To Roast The Best Kona Coffee
The best type of roasting machine has hardly changed in 60 years, amounting more or less to a heavy steel drum which spins on its side. Vanes inside the rotating chamber tumble the Kona to ensure an even absorption of heat, which is administered by a series of gas burners. Thermometers inside the drum measure bean and air temperatures.
The most important part of the machine looks roughly like a garden trowel with the blade curled up. Inserted into the cascade of roasting coffee through a sleeve in the roaster door, the tryer (as it’s called) catches small samples of roasting coffee. Withdrawing this scoop periodically, then incessantly as a batch races to completion, the roaster is able to examine the coffee at close hand.
First Fire Brings the Kona Coffee to Life.
Coffee is roasted at more than 400ƒF, but when the machine is charged — when several hundred pounds of coffee are dropped in–the temperature dips dramatically. Within three minutes, awakened by the gathering heat, a grassy fragrance radiates from beans turned an intense, blanched-vegetable green.
At five minutes, bright green fades into yellow, then deepens into harvest gold and tawny brown. The smell of toasted wheat fills the air, and the coffee begins to swell. Around nine minutes, sometimes later, the roast looks ruined. The bean color is suddenly mottled, the surface wrinkled. The silverskin buckles and flakes. The roaster is patient but watches carefully for the coffee to smooth out.
Coffee is relatively elastic. It will double in size during roasting due to the expansion of gasses, and it will lose 20% of its weight (mostly in water vapor) due to the escape of those gasses. But after ten minutes in 450ƒF heat, the internal pressure is sufficient to rupture a quantity of cells.
The popping sound this creates is one more indicator of the roast’s progression. The roasters can hear it over the roar of the machine and through the tryer port as they pull the small scoop again and again to smell, look, and now to listen.
Expansion smoothes the bean surface and shrugs off the silverskin. The color evens out. This is cinnamon, or light American roast, and cost-conscious roasters stop here while the beans still hold some water weight, but it’s a cruel way to wring out an extra dollar. The flavor is profoundly sour and the body limpid.
Around eleven minutes the popping gradually subsides, and the color changes from sienna to chestnut brown. A lot of folks get off here and call it full city, but then a lot of folks got off in Missouri and called it the West. To get the most flavor out of the coffee, keep your seats for the wild ride into second pop.
At high noon in the roasting cycle, the roaster works the tryer like a piston. Color and aroma change by the second. During most of the roasting process, coffee absorbs heat. But at this stage, just as in first pop, the beans suddenly expend heat, emitting a crackling sound.
Not Just Dark Roast Kona. The Perfect Dark Roast Kona.
Somewhere in the neighborhood of 15 minutes we arrive at dark roast. When the roasters’ senses say it’s precisely the right moment they spill the smoking coffee out onto a cylindrical cooling tray, where a mechanical sweep and forced air quickly halt the roasting process.
“Body” (the palatal sensation of heft or viscosity) generally increases as a roast progresses, potentially at the expense of a highly desirable quality, known in tasting terms as “acidity.” It is this pleasant sharpness, tartness, or effervescence that may be lost in indifferent dark-roasting. Proper dark roasting gets as much body out of the coffee as its specific flavor and acidity will allow. Ultimately, it’s the greatest test of the roasters’ craft.
Big Island Kona Coffee Growers – Kailua Kona, Hawaii