By Jess Brooks – Coffee Buyer & Supply Chain Manager
I remember teaching Coffee Basics classes to Allegro Coffee team members 10 years ago. As a trainer, it was my job to share a taste of place through flavor profiles from the different coffee growing regions.
I always enjoyed tasting coffee from Sumatra the most. The distinct cup tells the tale of an origin that seemed almost unbelievable to me. A tale of a magical distant place where coffee is grown in the hills surrounding the world’s largest volcanic lake, from a super-volcanic eruption 74,000 years ago. The eruption incomprehensible, with global consequences essentially changing human population and climate of the world.
Visiting the Lake Toba region of Sumatra this year awakened that same sense of wonder. Coffee here is steeped in history. The region has developed a unique way of processing called “Giling Basah”, or wet-hulling, that is exclusive to this area. This method allows farmers to speed up the last steps of processing because they deal with lots of rain, little sun for drying, and high humidity.
Unique Methods of Growing & Processing Coffee in Sumatra
Coffee in the Lintong region is grown small garden plots at 1400-1500 meters above sea level, among vegetable crops such as corn, peppers and cabbage. Farmers grow these inter-planted crops for the family’s consumption or to sell at local markets.
Plants here are incredibly lush and green. The soil is rich in nutrients from all the volcanic ash that has worked its’ way into the ground over the thousands of years. Walking around the farms was like walking on a pillow. The soil, light and fluffy, with little compaction – an ideal environment for all kinds of plants.
Individual farmers pick the coffee cherries and pulp them at home and ferment overnight. Then, they bring the wet parchment (call “Agaba”) to a collector. Some farmers bring as little as one to two kilos to the collector at a time. The collectors buy agaba from the same group of trusted farmers from year to year.
Next, the collector pre-dries the agaba for a half day before moving onto the wet-hulling. The huller removes the parchment, but the bean still has a very high moisture content at this point – about 35%. The beans (now called “labu”) are then laid out on patios in covered greenhouses where they dry for around five days.
Lastly, the dried coffee (referred to at this point as “asalan”) is bagged and sent to the warehouse in Medan, where it is sorted and prepared for export.
Seeing the coffee beans shooting through the wet-hulling machine, dark greenish-blue and bloated with water, was a new sight to me. Sumatra receives a lot of rain, so coffee farmers developed this unique method to dry the coffee quickly.
The Sumatra Lintong Flavor Profile
The unique wet-hulling method produce a cup with a heavy body and notes of grapefruit and fresh herbs. Done well, this is the traditional “Lintong Profile” – a representation of this region in the cup. For our Sumatra Lake Toba, we work with two collectors in the region who buy directly from a supply chain of Rainforest Alliance certified farmers. These farmers grow their coffees under the strict standards of the certification producing a sustainably delicious coffee. The result is a cup that invokes the feelings I had tasting this coffee during Coffee Basics classes – a taste of place unique to anywhere else in the world.