Sumatra…It’s Complex

Having just returned from my trip to Sumatra, I’ve had an opportunity to mull over the curiosity that is Sumatra. Most of our partnerships with small farmers are in Latin America so it’s certainly thought provoking to explore a completely different coffee growing culture that exists on the other side of the world.

Indonesia is the world’s fourth largest exporter of coffee and Sumatra represents a large portion of those exports. Coffee from Sumatra is complicated. It typically has a heavy body rivaled by few, has moderate to low acidity, and exhibits a flavour somewhere between earth and dark or dried fruits. When it’s good it’s unique like few other coffees save Ethiopia and when it’s bad…well…it’s bad. Finding consistent quality and flavour profile can be very difficult. For some, this is the beauty of Sumatran coffee, for us it can be really frustrating when we are trying to maximize quality and consistency in our blended and single origin coffees.

This challenge exists due to a combination of a complicated drying process and a complicated chain of individuals involved in the process from harvest to export.

The Drying Process:

Around the world there are a number of ways to get coffee cherries from the tree into jute bags in the form of export-ready green coffee. Here’s a very simple breakdown of the main methods:

  1. Washed or Wet-Processed Coffee

The majority of coffee-producing countries produce what is called the “washed” coffee using the wet process. In its most simple form this consists of removing the skin and thin layer of fruit from the fresh coffee cherry, washing the pergamino (which are the green coffee beans wrapped in a “skin” called parchment) with water, drying the pergamino from a moisture content of approximately 50% to 10-12%. The parchment is then removed and the green beans graded and sorted mechanically and/or by hand just prior to export.

  1. Natural or Dry-Processed Coffee

This is the simplest way to process coffee and doesn’t require water which is beneficial in places that struggle with water availability. In this method, the ripe coffee cherries are picked and immediately dried with the fruit and skins on the bean until the green beans are between 10-12% moisture. Then the dried fruit, skin and parchment are removed from the green beans and the green beans mechanically and/or hand sorted just prior to export.

  1. Partially Washed/Honey Processed Coffee

This is somewhere between Washed and Natural. The skin and fruit of the cherries is removed to varying degrees mechanically but the pergamino is never washed completely free of fruit and skin residue. The pergamino is then dried to the usual moisture level and the parchment is removed, beans sorted and then exported.

These three processes or versions of them are in use in different coffee-producing countries around the world but in much of Indonesia and particularly in Sumatra, there is what is called the “wet-hulled” or in Indonesian, giling basah process. Here’s how it goes:

  1. Coffee cherries are picked and the pergamino is washed as with washed coffee.
  2. The pergamino or gabah in Indonesian, is dried from 50% to about 40% moisture content.
  3. The gabah is then “wet-hulled” by removing the parchment while the bean is still at 40% moisture content. These wet-hulled beans are called labu.
  4. The labu is then dried in the sun until it reaches anywhere between 18 and 25% moisture content.
  5. At 18-25% moisture, the coffee beans are called asalam and are typically sent to the exporter for the last step.
  6. The asalam is the then dried down from 18 to 13% moisture content into what is called “green export” (in Indonesian too) before mechanical and/or hand sorting is carried out.

There are some variations in this method but the removal of the parchment before the green beans are dry enough for export is the defining factor in this process. The flavour profile of Sumatran coffee is very much a result of this process. Some might argue it is a defective process and only produces a defective cup of coffee but coffee drinkers like what they like and a perfect cup of coffee is a relative thing. There is no question it is unique. The challenge for us is to create a consistent “uniqueness” that we can rely on as coffee roasters and coffee drinkers.

The Chain of Ownership:

In Latin America, usually the small scale farmer will deliver dried pergamino to the exporter ready for milling and sorting. Sometimes there are central depulping stations where the cherries are stripped of the skin and fruit but in the end the co-op or farmer do all of the work to get it export-ready.

In Sumatra it’s different.

Often, in Aceh Province and much of Indonesia, the farmers deliver their cherries to the Kolektor (Collector in English) in the village. The Collector buys the cherries from the farmers and then sells the gabah or asalam to the co-op. Depending on the capacity of the co-op it may sell asalam to an exporter who will dry it down to green export or it will process the asalam into green export itself.

The extra and often problematic step is the Collector. Firstly, in many cases the collector is in reality a trader and if the transactions are not transparent and monitored regularly by the co-ops there is a risk that Collectors could take advantage of their position to buy low and sell high.

Secondly, depending on the Collector’s facilities, skill, and attention to detail in each village, this structure creates a large gap in the quality control process. If a collector is essentially working for themselves and being paid the same no matter the attention to detail then quality can suffer greatly. This leads to the inconsistent and “wild” flavour profiles that Sumatran coffee often exhibits.

We’re confident that a close relationship with Permata Gayo will lead to improvements though. During this visit we discussed better traceability so that we can identify the collectors that are doing the best job to produce consistent quality and flavour profiles. This way they will be able to keep these village coffees separate during the harvest and processing and ensure more consistent and higher quality lots make it into our containers and into our customers cups.