A dozen intrepid coffee hunters gathered in Medan, Sumatra, at the end of November for a field trip to Indonesia’s largest coffee-producing island. The group spent ten days visiting coffee growing regions in Aceh and North Sumatra provinces. Our host was our excellent milling partner -PT Sarimakmur – who Mercanta has been working with for over six years to select Sumatra’s pick of the crop coffees.

From Medan, the island’s largest city, the group set off almost immediately for the volcanic Lake Toba, in the heart of North Sumatra Province’s coffee country. This lush, fertile region produces much of the coffee that the commodity market has generically labeled ‘Lintong’, after a small town to the south of the lake. The group travelled into the highlands around the lake (at around 1200 metres in altitude) to visit traditional smallholder coffee farms.
These tiny farms are typical of coffee production in Sumatra, where most farms average one hectare or less – there are very few coffee estates or even co-ops on the island, instead a huge number of smallholders sell small quantities of coffee at their local village market. These farmers – many of whom are women – bargain hard and prices for semi-prepared coffee in the domestic market are very high compared to Latin American and African standards.
Most of these smallholders pulp their cherries at home using basic pulping machines, then very partially dry the mucilage before sending the crop on to millers to remove the parchment in a semi-wet state. This is called ‘semi-washed’, known locally as ‘Giling Basah’ (‘wet hulling’) – it is thought that this process gives Sumatran beans their distinctive bluish-green appearance.
From Lake Toba, the group then travelled on west to the Sidikalang district of North Sumatra to see a very different approach to coffee growing. Wahana Estate, which was started by Sarimakmur in 2005, is the only large coffee estate of its kind on the island. Around 250 hectares are planted out with a wide mix of varietals, which are carefully separated in order to produce distinct single varietal coffees, including some interesting local Indonesian hybrids – Rasuna, Long Berry, Andong Sari, Toraja, S795 (Indian Typica), Jantung – and more widely known international varietals – Caturra, Catuai, Villa Sachi and Colombia Típica varieties.
Unusually for Indonesia, most of the estate’s coffee is fully-washed – using the estate’s brand new wet milling facility, which can process an impressive 25 metric tonnes of red cherries per hour. The estate employs between 800 and 1000 workers, whose families have the use of an on-site health clinic.
After spending the night at Wahana Estate, the group headed back to Medan for a quick rest before the next day’s gruelling bus ride to Aceh, in the far north-west of the island. This is dedicated coffee country – with thousands of small, very traditional family farms in the region around Lake Laut Tawar. The group met some local growers, then visited Sarimakmur’s large milling facility in the town of Takengon, on the shores of the lake.
Back in Medan, there was just enough time to visit Sarimakmur’s main mill, which, despite its large size, is extremely well-managed, clean and modern.
All in all it was an intense but very rewarding trip. Indonesia is a fascinating origin, with some equally fascinating coffees – the finest and freshest examples can display complex herbal characteristics, a clean bright cup and a depth of flavour and weight of body that can rival a fine Colombian or Kenyan. One key conclusion to draw from the trip is that there is a massive mix of qualities available among the thousands of small lots that arrive at local mills. This is why our partnership with Sarimakmur is so important to us – only by sorting the pick of the crop coffees from the other grades can we be sure of securing the best that the island has to offer.
A big thank you to Maria, Andry and Hendri at Sarimakmur for being such splendid hosts, and to all those that took part for making the trip such a success.
Keep an eye on our UK warehouse for the arrival of our new line of Takengon and various single varietal microlots from Wahana Estate…