Several Common Coffee Bean Processing Methods: The Natural Process is So Simple and Crude

FrontStreet Coffee – An Introduction to Coffee Processing Methods

Washed Process

Washed coffee accounts for 35% of exports. High-quality washed coffee is processed from freshly picked, fully mature cherries, with careful harvesting and close monitoring by professionals. After sorting and cleaning, the cherries are pulped on the same day they are picked, then fermented, washed, dried, and hulled. During washing, special pulping machines separate the skin and pulp from the beans, which then go into fermentation tanks, where the mucilage loses its stickiness as its sugars are broken down.

Depending on the method, fermentation typically runs from 12 hours to 6 days (some growers use sprinkler systems, which usually take several days). Knowing when to stop fermentation is critical: once coffee over-ferments, its flavor turns excessively sour. When the sticky compounds in the mucilage have fully broken down, they are rinsed away with large volumes of water, leaving beans at about 12% humidity. The washed process yields good body, high aroma, and vibrant acidity.

Natural Process

Natural coffee accounts for 65% of exports, and the procedure is the simplest of all: after picking, the whole cherries go straight to sun-drying with no prior treatment—the oldest processing method still in use. It is mainly carried out by families, who lay the red cherries on cement floors or raised tables to dry to about 11.5% humidity before hulling and cleaning. Drying typically lasts about 4 weeks, and the process must be rigorously managed so the coffee loses none of its flavor; it also demands a very dry local climate. Natural beans have a full, natural body, a gentle aroma, and more mucilage sweetness.

Honey Process

The mucilage coating coffee beans is extremely sticky and rich in sugar, which is why it's commonly called "honey." In honey processing, some or all of that honey is left on the bean as it dries. After the cherries are picked, sorted, and depulped—removing the flesh and skin—they are laid out on drying beds. Because the remaining mucilage dries quickly, the beans undergo almost no fermentation during drying. Honey coffee is slightly more acidic than fully natural coffee, yet noticeably softer in acidity than washed lots. Based on how much mucilage remains—40% to 100%—honey processing is divided into four levels: 40%, 60%, 80%, and 100%. Some growers deliberately strip away part of the mucilage to keep the coffee from turning fruity through fermentation during drying.

Knowledge Point

The best crops come from regions with higher altitude, fertile soil rich in phosphorus, nitrogen, and potassium, and a moderate climate.

FrontStreet Coffee Recommendation

To taste these methods side by side, FrontStreet Coffee offers benchmarks for each. For washed, try the Yirgacheffe Worka (Guodingding) Cooperative lot—traditional washing brings out jasmine florals and bright citrus acidity, with green tea and honey tones after a medium-light roast—or the Kenya "Cherry Tomato," whose double washing gives it an intensely juicy, sweet-tart cup of cherry tomato, dried plum, snow pear, and yellow sugar. For natural, the Yirgacheffe Red Cherry lot uses only fully ripe, all-red cherries sun-dried for 27–30 days on raised beds, producing elegant florals, bright acidity, pronounced tropical fruit, and a full fermented sweetness. And for honey, FrontStreet's Costa Rica Blackberry—black honey processed, with the mucilage left on through drying—delivers raisin and blueberry sweetness laced with osmanthus and rose fragrance, lovely as a pour-over, cold brew, americano, or latte.