Most of the coffee that most anyone drinks is washed coffee, or coffee that’s been wet processed. It’s the more reliable of the three methods, producing coffee with higher acidity, which is just another way of saying brightness.
The basic method begins with sending the just-picked coffee cherry through a pulping machine, which removes the outer skin while leaving the pulp (also called mucilage) clinging to the seeds inside. The pulp-covered seeds are then soaked in water and periodically agitated to encourage the pulp to fall off. Fermentation follows, where the seeds sit in water for anywhere between a few hours to a couple of days, depending on the climate, equipment used, and the producer’s preference.
Following fermentation, the beans are rinsed thoroughly and then dried, either outdoors on raised beds, or in a mechanical dryer. Climate and equipment dictate how many days this final step takes.
2. Natural/Dry Processed Coffee
Of the three methods, natural processing is the older technique, whereby whole coffee cherry dry intact on raised beds, patios, or mats. Once the fruit is entirely dry, it’s either stored for a period of months or hulled right away to remove the outer skin and the inner parchment. All that remains are the two seeds—known more commonly as beans.
Natural processing originated in places without reliable access to water, like parts of Ethiopia and Yemen. The technique makes sense there, where temperatures are hot and the sun is powerful. In these conditions, the drying coffee cherry have little chance to mildew, as compared to places like Cobán, Guatemala, where perpetual mist falls throughout harvest season.
When processed well, natural coffees articulate fruited flavors rarely experienced in washed coffees. Notes of blueberry and strawberry might perfume a cup, so that even those new to coffee tasting are able to pinpoint the exact flavor. In a very real way, the beans absorb essences of the fruit’s drying flesh. That’s why natural coffees exhibit a wide range of vivid fruited and sometimes wine-like notes, along with greater body and less acidity.
3. Honey Processed Coffee
The honey coffee process is the hardest and most demanding coffee processing method. The processor has to start by pulping the coffee and then spreads it out for drying without any washing to leave part of the pulp. The processor spreads the coffee beans thinly on special drying beds and turns them after every one hour for 10-15 days to gain the needed stability.
The result is usually a coffee with fine elegant attributes associated with the high-end washed coffee coupled up with substantial fruit and body sweetness of the natural coffee. In Central America, this process is refined and includes yellow, white, black and red styles.