Wet-hulling, or giling basah in Bahasa Indonesia, is a distinctive coffee processing method developed in Indonesia to adapt to the country’s humid, rainy climate. Unlike most coffee-producing regions that use washed, natural, or honey processes, wet-hulling remains almost exclusive to Indonesia, especially on the islands of Sumatra and Sulawesi. Its uniqueness lies not only in the technique but also in the rich, full-bodied flavor it imparts to the coffee.
The process begins with freshly harvested coffee cherries, which are pulped to remove the outer skin. The beans, still coated with sticky mucilage, are partially fermented and washed to remove only some of this layer. At this stage, the beans are dried briefly, reducing their moisture content to around 40–50%. While most coffee would continue drying in its parchment layer until nearly dry, Indonesian farmers instead hull the beans while they are still quite wet—a step that gives the method its name. After hulling, the naked beans are spread out again and dried until they reach export-ready moisture levels of around 12–13%.
This unusual sequence produces coffee with a bold, earthy, and sometimes smoky profile, featuring a heavy body and low acidity. These characteristics distinguish wet-hulled coffees from the bright and clean flavors of washed coffees, which retain more acidity and sweetness. The deep, rustic notes of wet-hulled beans are particularly prized in blends designed for espresso or darker roasts.
Beyond flavor, the wet-hulling method offers practical advantages for farmers. Because drying to full parchment stage takes too long in Indonesia’s wet climate, removing the parchment early allows producers to sell their coffee sooner. This quicker turnaround provides much-needed cash flow, especially for smallholder farmers who rely on coffee as their main income source. However, the method also carries drawbacks: inconsistent drying conditions can affect bean quality, and wet-hulled coffees often command lower prices on the specialty market. Still, giling basah remains a vital tradition, deeply intertwined with Indonesia’s geography, culture, and coffee identity.
Wet-Hulling: Indonesia’s Unique Coffee Processing Method
