Sumatra coffee can be said to be the originator of full-bodied coffee, and it is also the main producing region of Mandheling coffee. It not only has a rich flavor and mellow taste, but can also be made into blended coffee or enjoyed as a single origin. Today, Front Street Coffee is dedicating this discussion to this coffee from Sumatra to explain just what its story is all about~

Sumatra Mandheling coffee is one of Indonesia's most representative coffee beans. Front Street currently has five Mandheling coffees with distinct flavors, selected from different origins, varieties, and processing methods, and even the roasting curves from Front Street's own roasting are different in each case. Speaking of roasting, many friends who have tried Front Street Coffee beans probably know that before launching each coffee bean, Front Street conducts extensive origin flavor identification training, then develops multiple roasting curves to cup and find the pour-over parameters that best suit that bean. Roasting is, apart from variety and processing method, the step that determines a coffee bean's flavor, which is also why Front Street insists on the own-roasting model.

Sumatra Coffee Beans

Indonesia is located in Southeast Asia, and its coffee history dates back to 1696, when Dutch coffee farm owners tried to find broader coffee-growing lands. After much exploration, they finally settled on Indonesia's Java Island. Over the course of 30 years, Indonesia had already established a sufficient foundation in the coffee market.

However, today the representative of Indonesian coffee is actually Mandheling from Sumatra, which is not really a surprising result, because from the beginning most of the Java coffee sold to Europe actually came from the Sumatra region, and Mandheling comes from Sumatra. So Sumatra can be said to be an important coffee-producing area in Indonesia.

The Story of Mandheling Coffee

Mandheling originally referred to the name of an Indonesian tribe, and the way it accidentally became the name of a coffee bean also has a story. After Japanese soldiers colonized Indonesia and returned to Japan, they could not forget the delicious local coffee, so through trade connections they asked the locals to help collect high-quality coffee beans, among which was this Mandheling. The Japanese were very fond of this coffee bean and asked for its name. Since the commercial source was inconvenient to disclose, the locals casually said "Mandheling," and thus Mandheling unexpectedly became the name of a coffee bean. The locals mentioned earlier are actually the owner of the Indonesian PWN company (Pwani Coffee Company) that will be discussed below.

Sumatra Coffee Beans' Unique Processing Method — Wet Hulling

Mandheling mostly uses Sumatra's unique coffee bean processing method — wet hulling. Because the local weather is mostly rainy, with constant typhoons, it cannot achieve the good weather required for sun-drying, and the local economy is not good either, so it also cannot use the more expensive washed method. This gave rise to the highly local wet-hulling method.

In the first stage, a wooden pulper is used to remove the skin and pulp. After fermenting for 3 hours, the beans are dried until the moisture content drops to 30-50%, half-dry and half-wet.

In the second stage, the mucilage and parchment layer are removed, and drying continues for the later stage. The drying process takes 2-4 days, and the moisture content drops to 12-13%.

Besides the regular wet-hulling method, there is also an aged wet-hulling method. The coffee beans first undergo ordinary wet-hulling, then are sealed and stored in a warehouse for 2-3 years. The warehouse environment must be cool and ventilated, and the beans must be turned regularly to prevent mold and spoilage. During this period, the acidity of the coffee beans slowly weakens and turns into sugar, and the color also becomes deeper, mostly yellowish-brown or dark brown. Mandheling coffee beans using this processing method are also called Aged Mandheling coffee beans.

Wet hulling creates Mandheling's special flavor. It can be said that Mandheling and wet hulling are bound together, but today's coffee market no longer settles for staying unchanged. Even if wet hulling is Mandheling's characteristic, there are also attempts with other processing methods, such as the sun-dried Mandheling from Wahana Estate. Changes in processing method also have requirements: while preserving the original flavor of the coffee beans, other flavors are added.

FrontStreet Coffee: Indonesia · Lintong Mandheling Coffee Beans
Region: Lintong producing area, Sumatra
Altitude: 1,100-1,600 meters
Variety: TimTim\Ateng
Processing method: Wet hulling
Flavor: Baked toast, nuts, caramel, pine, herbs

Lintong Mandheling is produced in the Lintong mountain area of north-central Sumatra, near Lake Toba. Lintong Mandheling is the regular version of Mandheling. Lintong Mandheling also uses the regular wet-hulling method, which creates its characteristics of low acidity and high body. But one situation that arises with wet hulling is that, because the semi-hard, semi-soft wet raw beans are easily crushed when the mucilage and parchment layer are removed, the beans are damaged and split open like a goat's hoof, commonly known as goat-hoof beans. This is not a defective bean, and can be said to be a very notable characteristic of Mandheling.

Lintong Mandheling does not put much effort into screening, and the lack of refinement in processing easily leads to instability in the coffee beans' output, but this does not diminish people's love for its full-bodied flavor.

FrontStreet Coffee: Golden Mandheling Coffee Beans
Region: Gayo Mountain, Aceh, Sumatra
Altitude: 1,100-1,600 meters
Variety: Ateng
Grade: G1, 3 times hand-sorted
Processing method: Wet hulling
Flavor: Spices, herbs, caramel, pine, nuts, chocolate

Since discovering Mandheling, the Japanese have always been very attentive to this coffee bean. In the course of cooperating with local green bean merchants, they established a strict screening system. After processing, the green beans undergo density and color sorting, and then are also hand-selected multiple times, finally presenting Mandheling with uniform color and uniform bean shape. It is said that when processing the green beans, the Mandheling under sunlight gives off a golden sheen, hence the name Golden Mandheling.

The specification of Golden Mandheling is 18 screen or above, with fewer than 3 defective beans (in a 300g green bean sample), belonging to the highest grade G1. Its color tends toward dark green, and its shape is neat flat beans. After strict screening, Golden Mandheling not only no longer has the earthy miscellaneous flavors unique to ordinary Mandheling, but also tastes cleaner and more transparent, with a stronger sweetness and fragrance.

However, the company that registered Golden Mandheling as a trademark was not a Japanese company, but the local Indonesian company that cooperated with Japanese companies in exporting Mandheling coffee beans in the early days — PWN Company (Pwani Coffee Company). The Japanese company instead registered "Gold Top Mandheling." In terms of flavor expression, the two are actually not very different, but because the brands are different and the merchants' marketing strategies are different, it is also possible that public opinion ends up differing. So as for which of the two Golden Mandhelings is better, opinions will vary.

Ateng is a hybrid variety between Arabica and Robusta, with several subtypes, widely planted in Sumatra and other small Indonesian islands. To put it plainly, it is a branch of Catimor, and Ateng is the local name.

FrontStreet Coffee: Tiger Mandheling Coffee Beans
Region: Sumatra
Altitude: 1,500 meters
Variety: Caturra, Typica, Sidikalong
Processing method: Wet hulling
Flavor: Nuts, cream, dark chocolate, caramel, pine

FrontStreet Coffee: Aged Mandheling Coffee Beans
Region: Sumatra
Altitude: 1,500 meters
Variety: Caturra, Typica
Processing method: Wet hulling
Flavor: Ripe pu'er, caramel, herbs, chocolate, relatively low acidity

When it comes to alcohol, everyone tends to think the longer it is stored, the better, hence the name aged wine. The same is true for aged coffee. Among aged coffees, Aged Mandheling is the finest. In fact, this unique flavor was not intentionally created. Indonesia was once a Dutch colony, and during the colonial period Indonesia continuously shipped coffee beans to Europe. To ensure an uninterrupted supply, coffee beans would be stored appropriately, but due to external factors such as the long transport distance, the shipping time became too long and the beans were also exposed to sea breezes. By the time the coffee beans reached Europe, another flavor had already formed, and this was the origin of aged flavor. Fortunately, at the time, the European colonists were amazed by this taste and quickly accepted and promoted this processing method.

Now the aging process for Aged Mandheling is quite mature. The coffee beans first undergo wet hulling (wet hulling is the process in ordinary washed processing in which the beans are sun-dried with parchment for 2-3 days to a moisture content of 20-24%, and finally the parchment is removed so the green beans dry to a moisture content of 12-13%), and are then sealed and stored in a warehouse. The warehouse environment must be cool and ventilated, and the beans must be turned regularly to prevent mold and spoilage. They are stored for 2-3 years, during which the acidity of the coffee beans slowly weakens and turns into sugar, and the color also becomes deeper, mostly yellowish-brown or dark brown, very recognizable.

The special processing method of Aged Mandheling gives it a rounder and deeper flavor, as intoxicating as pu'er.

FrontStreet Coffee: Sun-Dried Mandheling Coffee Beans
Region: Lake Toba, Sumatra
Estate: Wahana Estate
Altitude: 1,000-1,700 meters
Variety: Bourbon, Typica
Processing method: Sun-drying
Flavor: Melon, fermented aroma, mango, tropical fruit, peach

Wahana Estate was established in 2005 and is located near LeaMungkur village in the Sidikalang district of North Sumatra, Indonesia. Sidikalang has been one of Indonesia's famous coffee-producing areas since ancient times. The area where Wahana Estate is located has an altitude between 1,200-1,500 meters, annual rainfall of 2,000-3,000 millimeters, and in addition this area also has a relatively cool climate and a day-night temperature difference of more than 10°C. Based on the above conditions, the sugar content of the red cherries produced by Wahana is above 13%.

Wahana Estate is still a relatively young estate that continues to develop year by year. The estate covers an area of about 500 hectares. The estate owner plans to expand the estate's coffee-growing area as much as possible in the coming years. Wahana Estate isolates different coffee varieties by plot and harvests them separately to unleash the potential of each variety. In addition, only red cherries can be harvested, and then processed separately.

Roasting Comparison

FrontStreet Coffee Golden Mandheling Roasting Record Sheet

FrontStreet Coffee Lintong Mandheling Roasting Record Sheet

FrontStreet Coffee Tiger Mandheling Roasting Record Sheet

FrontStreet Coffee Aged Mandheling Roasting Record Sheet

FrontStreet Coffee Sun-Dried Mandheling Roasting Record Sheet

Pour-Over Flavor Comparison

When Front Street brews Mandheling coffee beans, it tries to keep the brewing parameters as consistent as possible. Since the sun-dried Mandheling uses a medium-light roast, while the other four Mandhelings use a medium-dark roast, coffee beans with different roasts use different brewing parameters.

Brewing parameters for light-medium roasted coffee beans: V60 dripper, 1:15 coffee-to-water ratio, 15g coffee dose, 90°C water temperature, grind size (80% passing through a No. 20 standard sieve)

Brewing parameters for medium-dark roasted coffee beans: Kono dripper, 1:15 coffee-to-water ratio, 15g coffee dose, 88°C water temperature, grind size (70-75% passing through a No. 20 standard sieve)

Front Street uses staged extraction, blooming with 30g of water for 30 seconds, then pouring in a small stream in circles until 125g for the stage break. When the water level drops and is about to expose the coffee bed, continue pouring until 225g and stop. When the water level drops and is about to expose the coffee bed, remove the dripper. (Timing starts at the beginning of blooming.) The V60 dripper extraction time is 2'00", and the Kono dripper extraction time is slightly longer, at 2'10".

【Flavor Description】
 Golden Mandheling: Layered and varied, full-bodied and clean, highly balanced, with rich nut and caramel aroma, a chocolate note, and a lasting finish.

Lintong Mandheling: Herbal and medicinal notes on entry, dark chocolate, caramel, and a sweet aftertaste. Tiger Mandheling: Pine and spice aromas, a relatively balanced mouthfeel, with obvious cream, dark chocolate, and nut flavors.

 Aged Mandheling: Aromas of wood, malt, and caramel rush to the nose. On the palate, it has less of the wildness of traditional Mandheling and more mellowness and refinement, with a sense of mature steadiness. Acidity is relatively low, and on entry there are flavors of ripe pu'er, caramel, herbs, and chocolate, with abundant sweetness.

Sun-Dried Mandheling: Tropical fruit, fermented feel, moderate acidity, smooth mouthfeel, obvious sweetness. 

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The above content is compiled by CoffeeHunters, a coffee news website.