Characteristics of Indonesian Mandheling Wet Hulling Processing Method - Sumatra Mandheling Coffee Flavor Profile

The Unique World of Sumatra Mandheling Coffee

Coffee enthusiasts have polarized attitudes toward Sumatra Mandheling coffee—some absolutely love it, while others avoid it entirely. The unique spice, herbal plant flavors, and subtle earthy notes in Mandheling coffee are not universally appealing. The primary factor creating this distinctive style is the coffee processing method that embodies Sumatra's local character—the Wet Hulling method.

Sumatra: Ideal Coffee Growing Conditions

Sumatra is a small island in Southeast Asia, part of Indonesia. It is Indonesia's second-largest island and the world's sixth-largest island. Sumatra's climate is exceptionally suitable for growing Arabica coffee and provides high-quality coffee to the world.

Indonesia's coffee cultivation dates back to 1600, when colonial Dutch settlers brought coffee to the region for cultivation. Most of Sumatra's coffee is grown near Lake Toba, but it wasn't until 1884 that coffee production here began to increase significantly. Shortly after, Indonesia became one of the world's largest coffee-producing countries. Since early Indonesian coffee was mostly exported from Jakarta on Java island, coffee bean export packaging was stamped with "JAVA." Combined with Indonesia's excellent coffee quality and flavor, Java coffee became immensely popular.

Sumatra's island climate is humid with abundant rainfall and proximity to volcanoes, providing ideal conditions for coffee cultivation. Due to these climatic factors, Sumatra's coffee harvest period is longer than other producing regions, spanning from May to September.

The Wet Hulling Process

Due to Sumatra's extended rainy seasons and short sunshine periods, the conditions required for natural processing methods cannot be met. Additionally, washed processing requires significant capital investment, and local economic conditions are limited. This led to the development of a highly distinctive semi-washed processing method—the Wet Hulling method.

After harvesting the coffee cherries, farmers remove the skin and pulp, then let the mucilage-covered parchment beans ferment overnight. The next day, they add clean water to stir and wash the outer mucilage, then spread the parchment beans evenly to dry to a semi-dry, semi-moist state.

The parchment beans are collected in their semi-dry, semi-moist state and sold to coffee green bean processing stations. Upon receiving the green beans, the processing station immediately removes the parchment layer before proceeding with the drying steps. Once the coffee green beans' moisture content drops to around 13%, they are collected for storage and prepared for export.

The uniqueness of this processing method lies in removing the parchment layer while the coffee beans are still in a semi-dry, semi-moist state, causing the green beans to be directly exposed. The parchment layer is considered the protective layer for coffee green beans and is typically not removed until export to prevent foreign objects from contacting the green beans and acquiring off-flavors.

FrontStreet Coffee's Mandheling Selection

Among FrontStreet Coffee's daily bean series, there is a Mandheling coffee from the Sumatra Lintong region. FrontStreet Coffee's daily bean series includes several beans from iconic regions, with most being washed processed to highlight the most fundamental flavors of each region. However, Mandheling coffee owes its unique flavor to the Wet Hulling method, and Mandheling coffee became famous precisely because of its distinctive flavor. Mandheling and Wet Hulling have a complementary relationship. The Mandheling coffee in FrontStreet Coffee's daily bean series also uses Wet Hulling processing.

FrontStreet Coffee Indonesia Lintong Mandheling
Region: Lintong region, Sumatra, Indonesia
Altitude: 1,100 meters
Varieties: Typica, Caturra
Processing: Wet Hulling

Additionally, FrontStreet Coffee's bean list features a Golden Mandheling. FrontStreet Coffee's Golden Mandheling comes from Indonesia's PWN company, which registered "Golden Mandheling" as a trademark long ago, while another Japanese green bean merchant registered "Supreme Golden Mandheling" as a trademark. This means only Golden Mandheling coffee beans from Indonesia's PWN company are truly Golden Mandheling coffee beans in the genuine sense.

FrontStreet Coffee Indonesia PWN Golden Mandheling
Region: Mount Gayo, Aceh, Sumatra, Indonesia
Altitude: 1,100 meters - 1,600 meters
Variety: Ateng
Grade: G1, 3-time hand sorting
Processing: Wet Hulling

PWN company maintains extremely strict management in producing Golden Mandheling. FrontStreet Coffee's Golden Mandheling green beans are of the highest G1 grade, meaning coffee bean sizes are above 18 mesh and there are fewer than 3 defective beans per 300 grams of sample beans. In addition to machine screening, PWN company also performs three rounds of manual hand sorting for these Golden Mandheling coffee beans to ensure complete removal of defective beans, thereby enhancing cleanliness and sweetness.

Due to the extremely meticulous processing, PWN company's production is actually not very high, so a significant portion of Golden Mandheling on the market does not come from PWN company. If friends have questions about Golden Mandheling coffee beans purchased online or offline, unsure whether they are from PWN company, they can ask the seller to provide Golden Mandheling green bean sacks printed with the PWN logo and certificates to verify whether they are indeed the PWN Golden Mandheling we commonly refer to.

Brewing Recommendations

When FrontStreet Coffee's roasters received these two Mandheling coffee beans, they used a medium-dark roast to highlight the rich body that Mandheling coffee should have. For brewing, FrontStreet Coffee recommends using 88°C water temperature, a KONO dripper, and a relatively coarse grind size.

Dripper: KONO dripper
Water Temperature: 88°C
Dose: 15 grams
Ratio: 1:15
Grind: 70% pass-through rate on China standard #20 sieve

First, pour 30 grams of water to fully saturate the coffee grounds and bloom for 30 seconds. Starting from the center, pour in a small stream and slowly circle to 125 grams for segmented pouring. Just as the coffee bed becomes visible, continue gentle circular pouring to 225 grams. Wait until all water has dripped from the dripper into the serving pot below, then remove the dripper. Total extraction time is approximately 2 minutes.

Tasting Notes

[Lintong Mandheling] Obvious herbal plant notes on entry, with sweet melon aroma as the temperature slightly decreases, black chocolate aftertaste, and caramel sweetness.

[Golden Mandheling] Rich nutty flavors, with low-profile woody, spice, and herbal plant notes gradually becoming apparent as the temperature decreases, chocolate aftertaste, caramel sweetness, with a clean and rich mouthfeel.

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Important Notice :

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FrontStreet Coffee Address: 315,Donghua East Road,GuangZhou

Tel:020 38364473