What Are the Characteristics of Indonesian Sumatra Coffee? What is Wet-Hulling?

Indonesia: The Land of Rich Coffee Heritage

Indonesia is one of Asia's largest coffee-producing countries. While its coffee may not feature the fruity flavors or floral aromas typical of Ethiopian coffee, it is renowned for producing coffee with rich, aromatic flavors and a full-bodied profile. Among its most famous offerings is Mandheling coffee, which stands as Indonesia's most representative coffee variety.

The Origin Story of Mandheling Coffee

When discussing Mandheling coffee, many people assume it refers to a coffee variety. However, "Mandheling" is actually the name of an ethnic minority group from the northern highlands of Sumatra, Indonesia. The story dates back to World War II when Japan occupied Indonesia. During this time, a Japanese soldier visited a local coffee shop and was captivated by the exceptionally aromatic and smooth coffee. When he asked the owner for the coffee's name, a language barrier led to a misunderstanding—the owner thought the soldier was asking about his ethnicity and replied "Mandheling."

After the war ended, the soldier returned to Japan but longed for the coffee he had enjoyed in Indonesia. He arranged to import approximately 15 tons of coffee from Indonesia, which proved immensely popular in Japan. Thus, the name "Mandheling" became established and has endured to this day.

Indonesia's Ideal Coffee Growing Environment

The exceptional quality of Indonesia's coffee can be attributed to its unique environmental conditions. As the world's largest archipelagic nation, Indonesia consists of 17,508 islands with diverse topography featuring rugged mountains, hills, and approximately 400 volcanoes. Located near the equator, Indonesia primarily experiences a tropical rainforest climate with consistently high temperatures, abundant rainfall, and warm, humid conditions averaging 25-27°C throughout the year. The country's distinct wet and dry seasons, combined with fertile volcanic soil, abundant water resources, and warm, humid climate, create ideal conditions for coffee cultivation.

Indonesia's Coffee Growing Regions

Coffee is cultivated on multiple islands in Indonesia, with both Arabica and Robusta varieties grown simultaneously. The coffee-producing regions are primarily divided by island. Currently, coffee is mainly grown on Sulawesi, Bali, Java, and Sumatra islands.

Sumatra: The Home of Mandheling Coffee

Among these regions, Sumatra stands out as the most renowned, being the birthplace of Mandheling coffee. As Indonesia's largest island, Sumatra is primarily divided into two parts: the western Barisan Mountains and the eastern lowland plains. Arabica varieties are concentrated in the northwestern part of the island along the Barisan Mountains, particularly in the Gayo highlands of the Aceh Special Administrative Region and the Lintong region of North Sumatra Province. The Barisan Mountains provide numerous volcanic ranges and lakes that create ideal conditions for Arabica cultivation, while Robusta varieties are predominantly grown in the southeastern lowland areas of the island.

Lintong Region

The Lintong region is located south of Medan, the capital of North Sumatra province. This area features Lake Toba, the world's largest volcanic crater lake, surrounded by high mountains. The soil in this region is rich in minerals due to past volcanic eruptions, and coffee is primarily cultivated on the slopes surrounding the lake at elevations between 1,400-1,800 meters.

Gayo Highlands

The Gayo highlands derive their name from the Gayo ethnic group and are located in the Aceh province at elevations between 1,300-1,600 meters. This region features numerous volcanoes and volcanic lakes, with the most famous coffee-growing area situated near Lake Lawar. FrontStreet Coffee's PWM Golden Mandheling originates from the Gayo highlands region.

Golden Mandheling: The Premium Selection

Golden Mandheling represents the premium tier among Mandheling coffees, with the term "Golden" highlighting its exceptional quality. However, "Golden Mandheling" has been registered as a trademark in Indonesia by PWN (Pwani Coffee Company).

This coffee has gained significant recognition due to PWN company's extremely strict production standards. After selecting beans larger than 18 screen size and meeting the highest Grade G1 standards (with fewer than 3 defective beans per 300-gram sample), the coffee undergoes three additional rounds of manual sorting. This meticulous process results in uniformly shaped PWN Golden Mandheling beans that deliver a clean, bright cup profile with intense sweet flavors.

Wet Hulling: The Unique Processing Method

Beyond quality selection, the distinctive wet hulling processing method creates the unique Mandheling coffee flavor profile. Wet hulling, also known as Giling Basah locally, was developed due to Indonesia's humid, rainy climate and frequent typhoons, which make the dry weather conditions required for natural processing difficult to achieve.

The wet hulling process begins similarly to the washed processing method. After harvesting, coffee cherries undergo float sorting in clean water, followed by removal of the outer skin and pulp while preserving the mucilage and parchment layer for fermentation. After fermentation completes, the beans are sun-dried until they reach a moisture content of 30-50%, at which point a hulling machine removes the parchment layer. The beans then undergo final drying until their moisture content drops to 12%. This approach significantly reduces drying time and allows coffee beans to dry more quickly.

FrontStreet Coffee's PWM Golden Mandheling Profile

As a result, FrontStreet Coffee's PWM Golden Mandheling offers a rich and intense flavor profile with a distinctive character. It presents notes of toasted bread, pine, cocoa, and subtle herbal flavors, with a clean, balanced mouthfeel and a caramel-sweet aftertaste.

Important Notice :

前街咖啡 FrontStreet Coffee has moved to new addredd:

FrontStreet Coffee Address: 315,Donghua East Road,GuangZhou

Tel:020 38364473