Traditional Sumatran coffees are wet-hulled aka Giling Basah in Bahasa Indonesian language. This can produce many defects though.
Giling Basah is also sometimes called An uncertain term to describe a coffee processing technique somewhere between wet-process and dry-process: Semi-washed has been used, most commonly in Brazil, to describe a hybrid coffee process. But it is uncertain if the term coffee which may or may not be accurate since there are variations in methods. But wet-hulled is more exact, for these types of coffee are stripped out of the protective Green coffee still in its outer shell, before dry-milling, is called Parchment coffee (pergamino). In the wet process, coffee is peeled, fermented, washed and then ready for drying on the patio, bed, or a mechanical layer when the coffee seed measures 25-50% moisture content. (Wet-process coffees are hulled when the coffee is rested for weeks-to-months and at 11% moisture or thereabouts).
When the coffee has so much moisture, it is fragile. It is not the dense hard dry bean we know of as exportable Green coffee refers to the processed seed of the coffee tree fruit. Coffee is a flowering shrub that produces fruit. The seeds of the fruit are processed, roasted, ground and prepared as an infusion.: Coffee, it can be torn in two between your fingers.
\So inevitably wet Hulling is the step at the dry mill where the green coffee bean is removed from the parchment shell. (See Wet Hulled for the Indonesia method). damages a lot of the coffee in the process. Then the unprotected green bean is laid out to dry on patios where it can be further damaged.
Indonesians are available as a unique wet-hulled or dry-hulled (washed) coffees. Giling Basah is the name for the wet-hulling process in Bahasa language, and will have more body and often more of the "character" that coffee goes through a lot. It is prepared by hand before export, but the level of prep and just how many of these defects you can cull out on a conveyor belt depends greatly.
Here is damage I found in a reject sample, showing a lot of physical damage, mold and other signs of re-wetting on the patios, Coffee Berry Borer (Hypothenemus hampei) insect damage, and nutritional problems at the coffee shrub. It’s a smorgasbord. Enjoy! -Tom