This is a classic Giling Basah (wet-hulled) coffee. Pulping is done by each farmer, then “wet hulling” is done at a central facility near Tanah Karo. Each farmer pulps, ferments in poly bag for 12 hours, then dries on patio for 3-4 days until the parchment reaches around 50% moisture. This “wet parchment” is then delivered to the central wet-hulling center (in Binjain, Meda, 3-4 hrs by tuck), where all the farmers’ coffee is collected and milled (parchment removed). The coffee is now in green form (no more parchment) and the green beans are then dried on patio down to 11%, at which point it is ready for final cleaning/sorting and export.
In 2010, Mt. Sinabung volcano erupted, and displaced these 50 refugees, who now live and farm near the towns of Berastagi and Kabanjahe in North Sumatra (north of Lake Toba). The group, predominantly women, was organized to learn coffee farming as a way to produce income in a new place, and on new land. While they now have 6+ years of coffee farming under their belts, their volume is still small so they intercrop heavily with fruits and vegetables to sell to local collectors and markets. Crop to Cup and our partners in Sumatra are working hard to introduce the new name of Tanah Karo to the specialty world and ensure proper training and pricing is in place for quality and yield improvements.
To talk about Sumatra we need to speak of its size. It’s large. Larger than Texas and Florida combined. In the middle of the island is a caldera called Lake Toba: the largest caldera from the largest volcanic explosion this world has ever seen. In this lake there is an island bigger than the country of Singapore. It is because of this lake that Sumatra has the largest rainfall seen by any coffee exporting country – the lake feeds clouds trapped in by the island’s 1500m tall mountains.
Sumatra is old. When Marco Polo visited the island’s northern tip back in 1292, he found the local people speaking Sanskrit, one of the purest remaining forms of the ancient language. When the Dutch East Indian Trading Company came, Aceh (and later Java) became the first commercial coffee origins that the world had seen.
Sumatra is big; I know we already said that, but it is really, really big. There are over 52 languages over four major ethnic groups (Acehnese, Minangkabaunese, Batak and Mala) covering an area over 170,500 square miles around. However big the island, however, there is only one government-authorized port of export – the 15 million person city of Medan. To get here, coffee has to travel as far as 375 miles, over massive mountains and on roads that are mostly still mud.
That’s 20 hours north to the producing regions Gayo Aceh, or 24 hours to the southern most Arabica regions in Kerinci. And this is the main reason that Sumatran coffee is hulled while wet, and dried while in the green. Called Giling Basah, this process starts with coffee parchment being dried to 30-50% moisture before being milled into green beans. Higher moisture during transport from the farm to the port can lend to the classic ‘earthy, musty’ flavors that you get in some Sumatrans.
Another source of Sumatra’s unique flavors dates back to the turn of the 20th century when Indonesia’s coffee crop was wiped out by leaf rust. Much of this was replaced with HDT (Hybrid de Timor) (Bourbon x Robusta), its direct descendant Tim Tim, or the more modern Sigarar Utang (Tim Tim x Bourbon).
And these are Robusta-Arabica hybrids; over the generations these have only added more Arabica through crossing Tim-Tim and with Sigarar Utang (Ateng). But there are pure Arabica strains as well, like Jember (Bourbon x Typica), USDA (Ethiopian Arabica transplant), and Onan Ganjan (Jember x Bourbon). So the genetic stock is absolutely unique.
But what makes Sumatra truly unique are Sumatrans. As a new generation takes the reigns, they are taking the country headlong into specialty. The past years have seen an explosion of washed coffees, naturals, honeys, new varietals, new regions and new ways of thinking about Sumatra’s role in specialty coffee. Not just locally, but regionally –Indonesian coffee has so much to offer, and so much of what comes out of Bali, Flores, Timor and Sulawesi comes through Sumatra.