What are the Characteristics of Sumatran Coffee: Origins and Story Behind the Name

FrontStreet Coffee's Mandheling coffee is produced on Sumatra Island in Asian Indonesia, also known as "Sumatran Coffee." It features very rich, aromatic, bitter, and full-bodied flavors with a touch of sweetness. Most coffee enthusiasts typically drink it as a single-origin coffee, but it's also an indispensable variety for blending coffee. In the era before Blue Mountain became world-famous, Sumatran coffee was considered the world's finest premium product. After roasting, the beans are quite large, with raw beans appearing brown or dark green. It has a special caramel-like aroma, rich and mellow flavor, sweet-bitter characteristics without soft acidity, but with distinct bitterness. Due to relatively low production volume, its price is slightly higher than typical coffee beans.

The Origin of Sumatran Coffee

As the largest island within Indonesia, Sumatra borders the Indian Ocean to the west and the South China Sea to the east, with the equator running directly through it. Additionally, it happens to be situated on the Pacific Ring of Fire, dotted with volcanoes that have brought fertile volcanic ash soil to this land. Mountainous areas perpetually shrouded in clouds and mist have considerable high altitude, abundant rainfall, and comfortable temperatures, making this land rich in resources, with coffee being one of the most suitable crops for cultivation.

The beginning of Indonesian coffee dates back to the late 17th century when the Dutch occupied Java Island, making it the headquarters of the Dutch East India Company in the East. The Dutch successively introduced two batches of Typica seedlings from India to Java for breeding. Before the 1870s, coffee growing areas were established on Sumatra Island, Bali Island, Sulawesi, and Timor, soon expanding from the original Java Island throughout Indonesia. However, this prosperity was short-lived. In 1869, the sudden coffee leaf rust disease swept through the entire Asian coffee region, including Indonesia, causing vast areas of Typica trees to wither and die.

To save the devastated coffee plantations, the Indonesian government introduced more disease-resistant Robusta varieties from Africa and other regions. Robusta remains Indonesia's main variety to this day. To ensure plant survival rates and increase coffee production, Indonesia continuously introduced various disease-resistant varieties from other countries. Among these, the Tim Tim, Bor Bor, and Catimor series Ateng - hybrids of Robusta and Arabica - due to their excellent disease resistance, abundant yield, and adaptation to Sumatra's terroir, quickly became prominent. Soon, Ateng and Tim Tim gradually replaced the original Typica varieties, becoming the main varieties in Sumatra and other regions, with the renowned specialty representative being Mandheling.

FrontStreet Coffee's Mandheling Coffee Growing Regions

Mandheling is primarily produced from two major lakes within Aceh Province and North Sumatra Province: Lake Toba and Lake Tawar.

Lake Toba is the world's largest volcanic lake and also Indonesia's largest high-altitude freshwater lake. The average annual temperature here is around 22°C, belonging to a tropical rainforest climate. The rainy and humid environment, combined with mountainous altitude of about 1,400 meters, produces various spices, timber, palm oil, and other agricultural products, including coffee of course. Under the gloomy and rainy weather, most fruit trees grow on higher altitude slopes, with several types of ferns covering their surfaces, collectively providing good sun protection for coffee, so growers don't need to adopt shade cultivation.

Located in the central Gayo Highlands of Sumatra's Aceh Province, there is a very unique microclimate environment near the famous volcanic Lake Tawar. Here the lake water is clear, the natural environment is excellent, and coffee trees are planted on mountains 1,200-1,800 meters high. Perennially shrouded in mist, with large temperature differences between day and night, the volcanic soil is rich in minerals and nutrients, with fallen fruit serving as fertilizer. Farmers widely use organic methods to grow coffee, coupled with a long planting history, making the coffee quality and yield from this region higher. Many green coffee merchants also value this area more, including the very famous local Pwani Coffee Company (PWN).

Each year from September to April of the following year is the coffee cherry ripening season, when you can see many farmers busy picking in the mountains. Traditional Lintong Mandheling is grown by the Mandailing and Batak ethnic groups, while the "rising star" Lake Tawar Mandheling is cultivated by the Gayo people.

Have You Heard of Wet-Hulling Processing?

The biggest difference from many coffee-growing regions is that Indonesia mostly has humid weather, with year-round humidity between 70-90%, typhoons can come at any time, and annual rainfall even reaches over 2000mm. Such harsh weather conditions simply cannot adopt the 2-3 week sun-drying method used in Africa. Washed processing is not only time-consuming but also requires more labor costs and water resources, which production-focused Indonesia cannot afford. Thus, they developed a unique semi-washed method - Wet-Hulling.

Coffee cherries with skin and pulp removed are directly poured into pools for brief fermentation of several hours. At this point, a small amount of mucilage still remains on the bean shell, which is removed through brushing. Next, the parchment beans are dried, with the first drying only needing to reach 30-40% moisture content, about 2-3 days, after which coffee farmers sell the green beans to buyers. The buyers will directly use machines to hull the purchased semi-dry parchment beans to obtain the innermost green beans.

Because the hulling machine uses greater friction to tear off the parchment layer tightly attached to the green beans, at this stage, white or green viscous liquid usually flows out. Due to long-term soaking in this liquid and the humid environment, the final green beans become soft, pale and swollen, forming a gray-green color. Through the stirring friction, the green beans are also more easily crushed or squeezed, especially at both ends, forming small gaps that create "elephant beans." The "naked beans" without parchment dry very quickly and are directly exposed to the humid environment, where various microorganisms thrive. This gives the coffee unique woody, spicy, and herbal plant aromas - what we call the "Mandheling flavor."

The Premium Choice Among Mandheling - FrontStreet Coffee's PWN Gold Mandheling Coffee Beans

As a representative of Sumatra Island coffee, Mandheling was originally a very small place name, which later gradually evolved into a designation for an ethnic group - the Mandheling people. The fame of Mandheling coffee originated from Pwani Coffee Company (PWN) successfully launching Mandheling in the Japanese market. Pwani is a trading company engaged in export business, founded by an overseas Chinese family from Quanzhou, Fujian. Located in the important Sumatran port city of Medan, it has been conducting export business since 1957, including products like rubber, cassia seed, cloves patchouli oil, and of course exporting Sumatran coffee beans to Japan.

Unlike many local Indonesian green coffee merchants, PWN Company is the exclusive supplier of high-grade Gold Mandheling coffee, having contracted the best Mandheling coffee growing regions in Indonesia, where the produced Mandheling beans are all superior products. The Gold Mandheling coffee that consistently occupies the top-right corner of FrontStreet Coffee's bean list is produced by PWN Company, and the Dongshankou store also displays the gunny sacks and certification certificates used for green bean packaging.

Wet-hulling saves much time and labor costs in green bean processing, but the rapid process also brings higher defect rates, so only strict manual selection can remove defects that machines cannot filter out. PWN Company subjects the purchased Mandheling green beans to one machine selection plus three manual selections, with quality far exceeding Indonesia's local highest G1 grade. To meet PWN Gold Mandheling production standards, the following requirements must be satisfied:

1. Green bean size: First manual selection of 18-19 screen or above
2. Fewer than 3 defective beans in a 300-gram green bean sample
3. Green coffee bean grade is G1 level
4. Dark green color, uniform size, neat shape

Before launching any coffee bean, FrontStreet Coffee conducts cupping to evaluate the coffee. Cupping is an evaluation of coffee bean quality and flavor, with unified standards that can more objectively identify the strengths and weaknesses of the flavors presented by the beans, as well as their characteristics. Through cupping, FrontStreet Coffee found that Lintong Mandheling daily drinking beans present rich nutty notes, with a hint of melon aroma in the finish. As temperature decreases, herbal plant flavors emerge, with a full-bodied texture and saturated aroma. PWN Gold Mandheling not only has aromas of dark chocolate, nuts, and caramel, but also herbal spice and pine flavors, with dark chocolate aftertaste, abundant finish, high clarity, and gentle fruit acidity as temperature drops.

FrontStreet Coffee's Gold Mandheling Optimal Pour-Over Method

FrontStreet Coffee's Gold Mandheling coffee has complex aromas. To enjoy the best flavor and texture, FrontStreet Coffee recommends using freshly roasted coffee beans for brewing. Coffee beans reach their optimal tasting period 4-7 days after roasting. After this period (about a month and a half), the aroma will gradually fade and develop woody defect flavors. FrontStreet Coffee believes that coffee bean freshness is particularly important, so shipped coffee beans are freshly roasted within 5 days. Adding logistics and shipping time, you can start enjoying them upon receipt.

FrontStreet Coffee's brewing approach for each coffee bean is based on the characteristics presented during cupping. For example, Gold Mandheling coffee has flavors of herbs, dark chocolate, caramel, nuts, and pine. For this type of full-bodied bean, FrontStreet Coffee's baristas use the Kono dripper. The Kono's ribs don't even reach half the dripper's height - this design is actually to ensure that after wetting, the filter paper closely adheres to the dripper wall, restricting airflow. This increases the water absorption time of coffee particles, resulting in more evenly extracted coffee overall and enhancing the full-bodied texture. Additionally, the groove skeleton at the bottom of the Kono dripper is a key design that allows subsequent brewing to produce a siphon effect.

Because dark-roasted coffee beans are more porous and absorbent, they can easily absorb too much water and become over-extracted, resulting in Mandheling coffee that is both bitter and astringent. Therefore, FrontStreet Coffee adjusts the grind to be coarser and uses slightly cooler water for brewing.

Recommended brewing parameters: Water temperature: 87-88°C | Coffee powder: 15g | Powder-to-water ratio 1:15 | Grind: Medium grind (70% pass-through rate on China standard #20 sieve)

The brewing method uses a three-stage pouring approach, divided into three pours to better express the full-bodied texture and caramel sweetness of Gold Mandheling coffee. The first bloom pour uses 30ml, completely wetting the coffee powder for degassing to better extract coffee flavor compounds in subsequent pours. The second stage pours 100ml, mainly to bring out Mandheling's golden foam and raise the powder bed. The final stage gently pours 95ml in the center. Wait for all coffee liquid to pass through, then remove the dripper and gently stir the coffee in the pot.

Hand-poured FrontStreet Coffee's PWN Gold Mandheling coffee is very rich, emitting herbal and spicy aromas, overall presenting a solid full-bodied texture, with caramel sweetness and chocolate, nut flavors.

Important Notice :

前街咖啡 FrontStreet Coffee has moved to new addredd:

FrontStreet Coffee Address: 315,Donghua East Road,GuangZhou

Tel:020 38364473