As we indicated in our post on washed coffees, dry process coffees (sometimes called “naturals”) are typically found in regions where water is preciously scarce. As such, this process has been used for generations to keep production costs low, though has historically yielded inferior commercial grade green coffee. An extraordinary level of care is required to produce quality dry processed coffees — so many things can go badly. Chances are, you’ve only had the good stuff.
Sorting. The first critical step in dry processing is sorting the unripe cherries from the ripe, red cherries at harvest. Unripe cherries can take a very long time to dry, and have a tendency to mold, over-ferment or rot, so sorting is essential.
Drying. After sorting, the coffee is spread over large drying beds that are typically made from nylon fabric or sometimes woven grass. The beds are suspended at about table-height to allow for maximum air flow, which helps keep moisture from collecting and contributing to unwanted fermentation. The beds also allow workers to hand sort any problematic fruit.
As the fruit dries, the sugars and taste characteristics of the fruit actually work their way into the bean. This has parallels to red wine-making, where the skins impart color, flavor and tannins during fermentation. As this transpires, the fruit becomes denser, and the layers between the outer skin and parchment dehydrate into a single layer of dried fruit that wrap the bean (usually in 2-3 weeks).
Once fully dried, the fruit is processed through a mechanical milling machine, stripping the dried fruit and reducing the beans down to their parchment layer. From here, the finishing steps are essentially the same as washed process coffees — the beans are stored in their parchment state for a rest period, which allows them to dry further before the eventual milling of that final parchment layer before shipping.
Taste. All of these meticulous steps require great care on behalf of the farmers and workers, but when done right, natural process coffees can have a remarkable flavor profile. Unlike washed coffees, naturals spend significantly more time enclosed in the cherry, and the resulting notes are often likened to blueberry and strawberry, as well as honey and other fruit notes. The process also contributes to less acidity than their washed counterparts.
In closing. Dry process coffees were, for most of history, considered inferior beans. Yet, as resources, knowledge and care continue to grow within the industry, so does the ability to “properly'' harvest and produce naturals. Today, the wonderful sugary fruit notes attributed to dry process coffees make certain lots some of the most sought after beans in the world.