Sumatran Coffee - An Introduction to Aged Sumatran Coffee Processing and Flavor Profiles

FrontStreet Coffee - Introduction to Aged Mandheling Coffee

The best-known coffee regions in Asia are the islands of the Malay Archipelago: Sumatra, Java, and Kalimantan. Among them, Sumatran Mandheling from the Indonesian island of Sumatra holds the highest reputation. It comes in two famous forms, Sumatran Mandheling DP Grade 1 and Premium Sumatran Mandheling. Sumatran Mandheling DP Grade 1 has a long aftertaste and a wild mountain fragrance, that distinctive earthy character of the primeval forest.

Indonesia's main coffee regions are Sumatra, Java, and Sulawesi, with Mandheling from Sumatra the most famous of all.

Mandheling is also known as "Sumatran coffee." Coffee from around Lake Tawar in the north can be called Aceh coffee or Lake Tawar coffee, while coffee from the Lintong and Lake Toba areas can be called Mandheling.

It comes mainly from two producing regions:

The first is Aceh, which covers five producing areas: Lake Tawar, Mount Gayo, the Gayo people, Aceh Mandheling, and Takengon Mandheling.

The second is North Sumatra, made up of four producing areas: Lake Toba, Lintong, the Mandailing people, and the Batak people.

Aged Coffee Bean Processing Method

Aged coffee beans are not simply green coffee that has been stored for a long time. That does not work: green coffee deteriorates over time. It fades from fresh green to white and then to yellow, turning bland and lifeless, and may even attract insects. Like aged wine, green beans must be properly processed and stored long term before they can honestly be called aged coffee.

Aged coffee beans, then, are green beans allowed to mature naturally through extended storage, typically 2-3 years. The changes along the way include reduced acidity, a shift in color, and increased bean density.

The storage environment must be cool and well ventilated. Because that environment is relatively dark and the storage period so long, aged coffee often develops complex flavors reminiscent of mold, or what people commonly describe as burlap or leather.

FrontStreet Coffee Recommendation

To taste how far this earthy, low-acid style can go, start with the FrontStreet PWN Golden Mandheling, the flagship of the PWN company in Indonesia. PWN applies exacting standards: beans must be 18 mesh or larger, and every 300 g green bean sample must contain fewer than 3 defective beans to meet the top G1 grade. On top of that come three rounds of hand sorting that remove defects entirely, lifting the cleanliness and the intensity of the sweetness. The beans are even, plump, and bright, and after a medium-dark roast they carry a rich roasted aroma with a clean cup, full body, and no sourness at all.

The traditional Mandheling heartland is Lintong, around Lake Toba in North Sumatra, and the FrontStreet Lintong Mandheling shows why. Grown and processed in the region where Sumatra's wet-hulled method and local fermentation give the coffee its famously wild character, it is roasted medium-dark to soften the acidity and play up the depth: a rich aroma, a heavy body, and a strong, stimulating cup with clove and woody notes, low acidity, a spicy and faintly minty edge, and a solid, lingering sweetness. For those who like their coffee bold and are not fond of acidity, this one is hard to beat.