Wet Hulled

What Is Wet Hulling?

Wet hulling (Giling Basah, Indonesian for "wet grinding") is a traditional method unique to Sumatra and Sulawesi in Indonesia. Because the humid, rainy climate makes long sun-drying difficult, farmers developed the practice of removing the parchment while the beans are still high in moisture — around 30–35%, sometimes higher.

Why Did It Develop?

In washed or natural processing, parchment coffee is dried to about 11–12% moisture before hulling, which can take one to several weeks. For cash-strapped smallholders, wet hulling means selling to collectors within days, and the exposed green beans dry faster, reducing the risk of mold in a humid environment.

Processing Steps

• Harvest: pick ripe coffee cherries
• Pulp: remove the skin with a simple pulper, often on the farm
• Short fermentation: ferment overnight in sacks or tanks (8–12 hours)
• Wash and pre-dry: wash off some mucilage and sun-dry to roughly 30–35% moisture
• Wet hull: mechanically remove the parchment at high moisture, when the beans are soft and easily damaged
• Final drying: dry the naked beans down to 12–13% moisture

Appearance

Wet-hulled green coffee is dark green to bluish-green, and many beans have crushed or dented edges — known in the trade as "goat's hoof" — caused by hulling them while soft.

Flavor Profile

• Herbal: grass, tobacco and cedar
• Earthy: rustic soil and mushroom notes
• Low acidity: almost no sharp acidity
• Heavy body: exceptionally full and thick

Quality Challenges

Because processing is spread across many farmers, collectors and mills, quality control is difficult, lots vary widely, and defects such as mustiness are more common. In recent years some cooperatives have improved drying equipment and practices, producing cleaner wet-hulled coffees.

Notable Regions

• Sumatra (Mandheling, Aceh Gayo, Lintong)
• Sulawesi (Toraja)

Brewing Tips

Wet-hulled coffee suits medium to medium-dark roasts. A French press or espresso amplifies its heavy body, and it pairs well with milk.