Giling Basah is a term used by Indonesian coffee processors to describe the method they use to remove the hulls of Coffea arabica . Literally translated from Indonesian, the term means "wet grinding".
The Arabica coffee industry also uses the term "wet hulled" to describe the same process. [1]
Most small-scale farmers in Sumatra, Sulawesi, Flores and Papua use the Giling Basah process. The mature coffee fruit, referred to as the coffee cherry, is harvested. This method is a pragmatic response to the region's humid, rainy climate, which makes it impractical to dry the coffee using more traditional methods that require weeks of consistent sun. [2] And farmers remove the outer skin mechanically using locally built pulping machines. The coffee beans, coated with mucilage, are stored for up to a day during which a natural fermentation breaks down the sticky residue. Afterwards the coffee beans, protected by a parchment hull (endocarp) are washed off before being let out to dry.
Contrary to other traditional drying methods, where the parchment coffee is dried until it reaches about 12% moisture content, the beans in the Giling Basah process are hulled when they reach between 30 and 35% moisture content; still semi-wet. The green coffee beans are then further dried to reach the exportable 12% moisture content. This operation gives the beans a unique bluish-green appearance and is thought to reduce the acidity and increase the body, resulting in the classic Indonesian cup profile. [3] The Giling Basah process also introduces additional flavours that can be vegetal or herbal, woody or musty, sometimes earthy. [4]
The Giling Basah process can create a "goat's foot," a split on one end, in green coffee beans. Sometimes the hulling machine partially crushes a soft bean, giving the bean a shape resembling a cloven hoof.
