Trengilling is a blend of single producer lots from across the Indonesian archipelago, Most farms are small. On average, farms are between 0.5 to 2.5 hectares. Coffee is usually the primary cash crop for farmers, but most also intercrop their trees alongside vegetables, maize and fruit. This intercropped produce will make up a substantial part of the family’s diet for the year.

In addition to growing coffee as a cash crop, many smallholder farmers also work as hired laborers at the nearby tea plantations. Tea is also a huge crop in the area. The bigger tea plantations are often near coffee farms. When the harvest is finished, coffee farmers will go there and pick leaves under contracted labor.

There are more and more initiatives by farmers to organize themselves into cooperatives. Individually farmers did not have When they’re in cooperatives, farmers can advocate for better prices for their cherry or parchment and cooperative members can share resources, organize training and negotiate better opportunities.

Indonesia is perhaps best known for its unique wet hulling process (giling basah). Though its exact origins are unclear, wet hulling most likely originated in Aceh during the late 1970s.

Wet hulling’s popularity can be attributed to producers’ need for prompt payments. It was also adopted specifically by many producers who lacked the drying infrastructure that was needed to shelter drying parchment from the high humidity and inconsistent rainfall typical in Sumatra. At higher elevations with constant humidity and unpredictable rainfall, drying can prove to be slow, risky and difficult.

The basic process for wet hulling is as follows: Cherry is harvested and pulped at or near the farm, on small hand-cranked or motorized pulpers. The coffee is fermented overnight (in small tanks, buckets, or bags) and washed with clean water the following morning. Parchment is sun-dried for between half a day and two days, depending on the weather, to allow for skin drying which eases the removal of parchment.

At this juncture the moisture content is between 30-40% and parchment is delivered to a processor (often by the village collector) for wet hulling. A wet hulling machine is larger, requires more power, and runs at a faster speed than a traditional dry huller. After the hulling, the coffee seed is whitish and pliable and is called labu. It is laid out to dry on tarps or patios, where it reduces in size and moisture to 14-15%. This stage the green coffee is known as asalan - unsorted and with defects.  Much of the internal commercial trade is for asalan.  Exporters, most of whom are based in Medan, will finish the drying down to 12-13%, sort and prepare for shipment.