Cultural Development History of Indonesian Coffee Beans: Growing Regions, Grading System, and the Flavor Characteristics of Mandheling

One of the world's most expensive coffees, Kopi Luwak, originates from Indonesia, and the most representative coffee is FrontStreet Coffee's Mandheling coffee. Mandheling coffee has moderate acidity, an extremely rich aroma, a relatively bitter taste, rich body, thick and full texture, combining fragrant, rich, mellow, and bitter flavors. Of course, for friends who don't like this taste, Mandheling coffee is like a cup of Chinese medicine - difficult to drink.

History of Indonesian Coffee

Indonesia is a major coffee producer in Asia and one of the world's top coffee-producing countries. Although Indonesia has the largest coffee planting area in the world, due to low coffee production efficiency, Indonesia's coffee production ranks third in the world after Brazil and Vietnam.

In 1699, when Indonesia was still under Dutch colonial rule, the VOC (Vereeniging Oust-Indies Company) introduced Arabica coffee plants to break the Arab global monopoly on coffee trade. The Dutch colonial government initially planted coffee around Batavia (now Jakarta).

More coffee plantations were established in East Java, Central Java, West Java, as well as parts of Sumatra and Sulawesi. Indonesia was the first place outside Arabia and Ethiopia to widely cultivate coffee. The VOC monopolized the coffee trade between 1725 and 1780.

By the mid-17th century, the VOC expanded Arabica coffee cultivation areas in Sumatra, Bali, Sulawesi, and Timor. On Sulawesi Island, coffee was first planted in 1750. In the North Sumatra highlands, coffee was first planted near Lake Toba in 1888, followed by the Gayo Highlands near Lake Laut Tawar (Aceh) in 1924. In the late 18th century, Dutch colonists established large coffee plantations in the Ijen Plateau of eastern Java.

In the 1920s, small farmers across Indonesia began growing coffee as an economic crop. However, disaster struck in 1876 when coffee leaf rust swept through Indonesia, eliminating most of the Typica variety. Robusta coffee (C. canephor var. robusta) was introduced as a replacement in East Java in 1900, especially in low-altitude areas where the rust was particularly severe.

The plantations on Java Island were nationalized at independence and revitalized with new varieties of Arabica coffee in the 1950s. These varieties were also adopted by small farmers through government and various development programs. Today, more than 90% of Indonesia's coffee is grown by small farmers on farms averaging one hectare or less.

Mandheling Coffee Growing Environment and Varieties

Indonesia is the world's largest archipelagic country, known as the "Country of a Thousand Islands." The islands are relatively dispersed, with mostly rugged mountains and hills within each island, only narrow plains along the coasts, surrounded by shallow seas and coral reefs. Indonesia has a typical tropical rainforest climate with an average annual temperature of 25-27°C and no distinct seasons. The northern region is affected by Northern Hemisphere monsoons with abundant rainfall from July to September, while the southern region is affected by Southern Hemisphere monsoons with abundant rainfall in December, January, and February, with annual precipitation between 1600-2200 mm. Indonesia's higher altitudes, volcanic ash soil, and climate characteristics provide excellent conditions for Arabica coffee tree growth.

In the late 17th century, the Dutch East India Company transplanted Arabica coffee trees from India to Jakarta on Java Island. Due to suitable climate and soil conditions, Arabica quickly spread to Sumatra on Java Island and another large island in the northeast, Sulawesi. However, in 1880, Java experienced a severe leaf rust outbreak that wiped out almost all Arabica plants. The Dutch switched to the disease-resistant Robusta coffee variety to stabilize Indonesia's coffee industry. To this day, Robusta remains the main force in Indonesian coffee, with Indonesian Robusta coffee accounting for approximately 85% of national production, distributed in low-altitude areas of Java and Bali. Arabica production accounts for 15%, distributed in higher altitude areas of northern Sumatra, Sulawesi, and Java.

The FrontStreet Coffee's Lin Dong Mandheling coffee variety is TimTim Ateng, and FrontStreet Coffee's Golden Mandheling coffee variety is labeled as: Ateng. In fact, TimTim is Timor, an Arabica variety with Robusta heritage, while Ateng is Catimor, a hybrid of Caturra and Catimor. These are just local names for the varieties.

Indonesian Coffee Growing Regions

Sumatra

A large island in western Indonesia, located on the equator, with an area of 473,000 square kilometers, it is the world's sixth-largest island. It faces the Malay Peninsula across the Malacca Strait to the northeast, borders the Indian Ocean to the west, and is divided by the equator. It belongs to the tropical rainforest climate and is right on the "coffee belt." The broadly defined "Mandheling" coffee comes from this island. Sumatra is not only the largest island in Indonesia but also the sixth-largest island in the world. It is located in the northwestern region of Indonesia. Due to its geographical location, Sumatra has the country's earliest harvest season from November to March.

FrontStreet Coffee's Lin Dong Mandheling comes from the Lin Dong mountain area in north-central Sumatra, near Lake Toba. FrontStreet Coffee's Lin Dong Mandheling is the regular version of Sumatran Mandheling.

Lake Toba, located in the center of North Sumatra Province, where Dutch colonists moved "Java Mandheling" north to the Lake Toba area in 1888, creating the modern Mandheling legend.

Lake Tawar, located in the center of the Aceh Special Administrative Region. It is at the northern end of Sumatra Island, with an area less than one-tenth of Lake Toba.

Currently, the highest quality beans in the entire Sumatra region come from the GAYO mountain area, mostly planted with old varieties. The Gayo mountains are located in the Aceh region of northern Sumatra province, with altitudes between 1500-2500 meters. Coffee farmers are mostly local farmers - the GAYO people. This region has ideal growing conditions for coffee - high altitude, fertile soil, abundant rainfall, and Lake Tawar provides rich water resources. The region widely adopts organic methods for coffee cultivation, without using chemical fertilizers, and is considered a world green coffee production area. Therefore, Gayo coffee is often called green coffee or Gayo organic coffee.

FrontStreet Coffee currently offers two Indonesian coffee beans, both from the origin of fine Mandheling coffee. "FrontStreet Coffee - Daily Series Lin Dong Mandheling Coffee Beans" shows flavors of toasted bread, nuts, caramel, pine, and herbs. "FrontStreet Coffee - PWN Golden Mandheling Coffee Beans" shows flavors of spices, nuts, pine, caramel, herbs, and dark chocolate.

Bali

Bali is famous for its beautiful beaches, coral reefs, and yoga and meditation retreats. This tropical paradise offers some of the best coffee that Indonesia and indeed the world have to offer. Most coffee grows in the Kintamani highlands located between the Batukaru and Agung volcanoes.

Mandheling Coffee Bean Grading System

Indonesia is located near the equator and has a tropical rainforest climate. Mass-produced coffee beans mostly use rough wet hulling processing. Wet hulling greatly accelerates the entire processing process. However, removing the still semi-dry parchment layer requires significant friction, so green beans are easily crushed and squeezed, especially at both ends, forming small gaps. Therefore, the defect rate of wet-hulled Indonesian coffee beans is generally high, so green bean merchants arrange manual hand-selection before export to remove incomplete defective beans.

Indonesian coffee grading mainly depends on the number of defective beans, supplemented by size grading. Indonesia's general quality requirements are no live insects, no moldy rotten beans, maximum moisture content of 12.5%, and impurity rate less than 0.5%. Graded by defect rate (based on 300g), the Grade standards are mainly divided into 6 levels, namely G1-G6.

Usually, the rough burlap bags containing Indonesian coffee green beans are marked with: country + grade name + green bean merchant. For example, both FrontStreet Coffee's Lin Dong Mandheling coffee and PWN Golden Mandheling coffee on FrontStreet Coffee's bean list are G1 grade. Among them, the green bean bag of FrontStreet Coffee's PWN Golden Mandheling coffee is printed with "PWN GOLDEN MANDHELING TRIPLE PICKED Grade 1 PROD OF INDONESIA 30KGS NET".

Golden Mandheling

Indonesia's PWN company, based on G1, conducted 1 machine selection + 3 manual selections, producing Mandheling green beans with uniform color and regular size, belonging to extremely high-quality Indonesian coffee beans. PWN is a famous Indonesian green bean acquisition company. They use 1 machine selection + 3 manual selections for wet-hulled Mandheling green beans to ensure that the produced batch reaches Indonesia's highest grade G1 level. The purpose of machine selection is to first screen out beans that must be above 18 mesh, with defective beans fewer than 3 (in 300g green bean samples), belonging to the highest G1 grade, with darker green color and regular flat bean shape. Subsequent multiple manual selections are to remove irregular defective beans. The reduction in defect rate greatly improves Mandheling coffee quality. To distinguish from regional Mandheling coffee, PWN registered "Golden Mandheling" as a trademark.

The Golden Mandheling coffee beans sold by FrontStreet Coffee are all from PWN company. In FrontStreet Coffee's offline stores, you can see PWN company's Golden Mandheling coffee bean certification and coffee bags printed with the company logo. Golden Mandheling is actually produced from Mandheling acquired locally in Indonesia by the company Pawani Coffee Company, which then registered the name Golden Mandheling. Therefore, the Mandheling produced by this company is actually the authentic Golden Mandheling. FrontStreet Coffee found that it not only lacks the unique earthy impurities of regular Mandheling but also tastes cleaner and more transparent, with stronger sweetness.

Mandheling Coffee Bean Processing Method - Wet Hulling

Mandheling's unique wet hulling method, also called wet shelling, is known locally as Giling Basah and is a traditional Indonesian coffee processing method. From the name alone, wet hulling seems similar to wet processing (washed processing method), however, the cupping flavors of these two processing methods are completely different. Wet-hulled processed coffee is usually thick and strong, with a very distinct personality.

Because the local weather is often rainy, with continuous typhoons, lacking long periods of sunlight, constantly high temperature and humidity, with humidity consistently between 70-90%, it's impossible to rely solely on sun-drying processing. The local economy is also limited, unable to use the more expensive washed method, which led to the development of the unique local wet hulling method. After completing the washed processing steps, the parchment-covered coffee beans are exposed to the sun for 1-2 days, until the coffee bean moisture content reaches 30-50%, then the parchment is removed for sun-drying, which can speed up the coffee bean drying process and greatly shorten the drying time.

The characteristics of wet hulling processing are phased, rapid drying and hull removal of parchment for drying. Teacher Han Huaizong described it as "This is also a rare processing method in the world, which accidentally created Mandheling's special low-acid, thick, and mellow flavor."

The "Goat Hoof" Shape of Mandheling Coffee Beans

Careful friends might notice the "goat hoof shape" characteristic of FrontStreet Coffee's Mandheling coffee beans. FrontStreet Coffee also noticed they share a common bean appearance feature: "goat hoof shape." This is because when semi-hard, semi-soft wet green beans are machine-processed to remove the mucilage and parchment layer, they are easily crushed, and the beans crack open like goat hooves, commonly known as "goat hoof beans." The "goat hoof shape" is a very significant characteristic of Mandheling coffee beans, so it's not considered a defective bean.

FrontStreet Coffee's Brewing Parameters for Mandheling Coffee:

FrontStreet Coffee's baristas choose the KONO dripper for brewing this type of thick-tasting coffee. Compared to V60, the KONO dripper has a smooth curved surface with weaker exhaust effect, and its straight ribs cover only one-quarter of the dripper, allowing coffee layers and hot water to form immersion extraction, resulting in a more rounded and mellow coffee taste. The KONO dripper is also suitable for full-flavored coffee beans like FrontStreet Coffee's Brazil Queen Manor coffee and FrontStreet Coffee's Jamaica Blue Mountain No. 1 coffee.

Dark roasting makes the internal structure of coffee beans loose, and we can crush them easily with a gentle pinch, which indicates strong water absorption after grinding into powder. To avoid excessive bitterness released after coffee powder absorbs water, FrontStreet Coffee will adjust the grind to be coarser and use lower temperature water for pour-over brewing. FrontStreet Coffee will use the common 1:15 powder-to-water ratio. If you want a stronger taste, you can use 1:13, adjusting according to your taste.

KONO dripper, 88 degrees Celsius water temperature, 1:15 powder-to-water ratio, 15g coffee powder, grind size (75% pass through No. 20 standard sieve), three-stage extraction.

Using segmented extraction, bloom with 2 times the water amount of coffee powder, that is, 30g water for 30 seconds. The reason for the blooming process is to allow the coffee powder to release internal carbon dioxide gas, thereby making the later extraction more stable. Use small water flow in circular motion to inject water to 125g for segmentation, continue injecting water to 225g then stop. Wait for the water in the dripper to finish dripping then remove the dripper. Start timing from the beginning of water injection, extraction time is 2'00". Next, pick up the entire cup of coffee and shake it evenly, then pour into cups for tasting.

[FrontStreet Coffee's Lin Dong Mandheling Coffee] Herbs, chocolate, caramel, overall relatively balanced.

[FrontStreet Coffee's Golden Mandheling Coffee] Nuts, spices, herbal plants, licorice, chocolate, caramel.

FrontStreet Coffee's Brewing Suggestions:

To brew a delicious cup of coffee, FrontStreet Coffee believes that any brewing method requires fresh coffee beans. FrontStreet Coffee has always believed that the freshness of coffee beans has a great relationship with the flavor of coffee. Therefore, the coffee beans shipped by FrontStreet Coffee are all within 5 days of roasting. FrontStreet Coffee's roasting philosophy is "freshly roasted good coffee," so that every customer who places an order receives the freshest coffee when it arrives. The coffee bean resting period is about 4-7 days, so when customers receive it, it's exactly when the flavor is at its best.

For friends who need ground coffee, FrontStreet Coffee kindly reminds: if coffee beans are ground in advance, there's no need for a resting period, because during transportation, the pressure from carbon dioxide in the packaging can also make the coffee flavor rounded, so you can brew a cup immediately upon receiving the coffee powder. However, coffee powder needs to be brewed promptly, because after coffee powder comes into contact with air, it oxidizes relatively quickly, meaning the coffee flavor will dissipate more quickly, and the coffee flavor won't be as good. Therefore, FrontStreet Coffee suggests buying whole beans and grinding fresh for each brew to better taste the coffee's flavor.

For professional coffee knowledge exchange and more coffee bean information, please follow Coffee Workshop (WeChat official account: cafe_style)

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Important Notice :

前街咖啡 FrontStreet Coffee has moved to new addredd:

FrontStreet Coffee Address: 315,Donghua East Road,GuangZhou

Tel:020 38364473