Giling Basah, also known as Semi-Washed, Sumatra Process, or Wet-Hulled, is a unique coffee processing method primarily used in Indonesia, particularly on the islands of Sumatra and Sulawesi.
This method is considered a variation of the traditional washed process and has become the hallmark of Indonesian coffee production. After being harvested, the coffee cherries are depulped to remove the outer skin, then fermented and partially dried.
Unlike conventional wet processing, where parchment coffee (with the mucilage and parchment intact) is dried until it reaches around 12% moisture, the Giling Basah process removes the parchment layer when the beans still have a moisture content of about 30–35%—hence the term “wet-hulled.” The beans, still semi-wet, are then dried again until they reach the standard 12% moisture level suitable for export.
The exact details of this process often vary between families and regions, having been passed down through generations. These traditional practices remain deeply embedded in local coffee culture. Meanwhile, government agencies and international coffee organizations frequently send agronomists and processing specialists to train farmers and introduce improved techniques—helping enhance the quality standards and export value of Indonesian green coffee.