How Does Wet-Hulling Shape Mandheling Coffee Flavor?
Mandheling, Sumatra's most representative coffee, is known for a full body, low acidity, and herbal bittersweet flavor. The name is a transliteration of the Mandailing ethnic group, and the cup profile owes much to Indonesia's traditional wet-hulling process. Front Street settled on four beans after sampling and cupping: Golden Mandheling, Lintong Mandheling, Tiger Mandheling, and Aged Mandheling.
Mandheling is usually dark roasted for two reasons: mixed varieties and processing leave a relatively high defect rate that dark roasting can mask, and Japanese drinkers who first popularized it favored mouthfeel over acidity. Producing areas differ widely in quality, so comparison matters. Front Street evaluates beans through roasting, cupping, and pour-over stages, and also offers a newer sun-dried Mandheling.
Mandheling is the most representative coffee of Sumatra, Indonesia, famous for its full-bodied, low-acid, herbal bittersweet flavor. But did you know that the name Mandheling actually comes from the transliteration of the Mandailing ethnic group? Its unique flavor is inseparable from Indonesia's traditional wet-hulling process. After extensive sampling and cupping, Front Street Coffee finally settled on four beans: Golden Mandheling, Lintong Mandheling, Tiger Mandheling, and Aged Mandheling. This article will systematically sort out the origin of Mandheling, its producing-area definition, the characteristics of the four major types, and the wet-hulling process, and will also introduce the latest sun-dried Mandheling brought in by Front Street Coffee. Finally, through green-bean comparison, roasting curves, cupping flavors, and KONO dripper brewing parameters, it will comprehensively present the charm of Mandheling coffee.
When Front Street Coffee procures any coffee bean, it goes through strict evaluation across multiple stages, including roasting, cupping, and pour-over. Even a single cup of coffee needs to be judged from multiple dimensions. Therefore, before Front Street Coffee finally decides to put coffee beans from a certain producing area on the shelves, it will compare at least three or more beans from the same producing area side by side.
The Mandheling we usually see is mostly dark-roasted, for two reasons: first, Mandheling's processing method and varieties are relatively mixed, resulting in a relatively high defect rate for this bean, and dark roasting can effectively conceal this shortcoming; second, Mandheling was first discovered by the Japanese, and Japanese coffee lovers tend to prefer mouthfeel-oriented expression when tasting. Therefore, it is not hard to understand why Mandheling chooses dark roasting. In recent years, Mandheling coffee has become increasingly popular thanks to its unique herbal, full-bodied flavor, and more and more people have come to accept it. However, there are many Mandheling producing areas and quality varies greatly. After extensive sampling and evaluation, Front Street Coffee finally determined four Mandheling coffee beans, namely Golden Mandheling, Lintong Mandheling, Tiger Mandheling, and Aged Mandheling.
I. The Origin of Mandheling
Mandheling is neither a producing area name, a place name, nor a port name or coffee variety name. It is actually the transliteration of the Indonesian Mandailing ethnic group.
During World War II, when Japan occupied Indonesia, Japanese soldiers drank delicious coffee locally and still could not forget it after returning to Japan after the war. So through their trade friends, they asked locals to help collect high-quality coffee beans, including this Mandheling. The Japanese loved this coffee bean very much and asked for its name. Because the commercial source was inconvenient to disclose, the locals casually said "Mandailing," and thus Mandheling unexpectedly became the name of a coffee bean.
The locals mentioned earlier are actually the owner of the Indonesian PWN company (Pawani Coffee Company), from which Front Street Coffee purchases Golden Mandheling coffee beans.
II. What Is Mandheling Coffee
The main coffee-producing areas of Indonesia include Sumatra, Java, and Sulawesi, among which "Mandheling" produced on Sumatra is the most famous. Mandheling is also called "Sumatra coffee." In the north, around Lake Tawar, it can be called Aceh coffee or Lake Tawar coffee; in the Lintong and Lake Toba areas, it can be called Mandheling. In the traditional strict sense, only coffee beans produced in the Lake Toba area (located in northwestern Sumatra, Indonesia) are called "Mandheling."
Mandheling has a heavy taste, with rich body and a lush, lively dynamism. It is neither astringent nor sour, and its body and bitterness can be fully expressed. The appearance of Mandheling coffee beans can be said to be the ugliest, but coffee fans say that the worse-looking Sumatra coffee beans are, the better, fuller, and smoother they taste.
III. What Are the Common Mandheling Types
Here are four Mandheling coffees from Front Street Coffee, namely Lintong Mandheling, Golden Mandheling, Tiger Mandheling, and Aged Mandheling.
1. Lintong Mandheling
A specialty Mandheling produced in the Lintong area, with relatively large beans and a relatively hard bean texture.
Indonesian coffee varies greatly in quality, but what we usually call Mandheling refers to coffee beans of Typica or its variants grown in the mountainous areas around Lake Toba. Coffee gourmets around the world have commented: Sumatra Mandheling coffee has the best texture in the world. Mandheling coffee beans are relatively large and hard in texture, and because there are many defects, strict selection is required during coffee processing.
Mandheling coffee is an indispensable variety in coffee blends. Its coffee flavor is rich, sweetly aromatic, purely bitter, and full-bodied, with a little sweetness and slight acidity.
Front Street Coffee Indonesian Lintong Mandheling coffee beans
2. Golden Mandheling
Golden Mandheling was trademarked by Indonesia's PWN company, making Golden Mandheling exclusive to PWN. Golden Mandheling is produced in the Gayo Mountains of Aceh, North Sumatra. The variety is Ateng. Ateng is a hybrid between Arabica and Robusta, widely planted in Sumatra and other small Indonesian islands. In fact, it is a branch of Catimor; Ateng is the local name. Golden Mandheling 19 mesh undergoes four rounds of manual selection, with higher quality requirements.
Front Street Coffee Indonesian Golden Mandheling coffee beans
3. Tiger Mandheling
Only Mandheling with more than 17 mesh and a defect rate below 4% can be called Tiger Mandheling. Because the main varieties of Tiger Mandheling are Caturra and Typica. Caturra has a citrus and lemon acidity in the mouthfeel, while Typica has a long-lasting sweet aftertaste, making Tiger Mandheling relatively balanced in mouthfeel and high in cleanliness.
Front Street Coffee Indonesian Tiger Mandheling coffee beans
4. Aged Mandheling
Aged coffee beans do not mean leaving green coffee beans for a long time; this is not acceptable, because green coffee beans will also spoil after being stored for a long time, changing from fresh cyan to white, then to yellow, becoming tasteless, and even growing insects. Like aged wines, green beans must undergo proper processing and long-term storage before they can be called truly aged coffee.
The so-called aged beans mean:
Allowing green beans to naturally age by extending storage time (usually 2 to 3 years). These changes include weakened acidity, changed color, and thickened bean texture. The storage environment must be cool and ventilated. Because the storage environment is relatively dark and the time is long, aged coffee always inevitably carries complex flavors such as a moldy smell or what is commonly called burlap or leather.
Front Street Coffee Indonesian Aged Mandheling coffee beans
IV. Mandheling Coffee Processing Method
Mandheling's unique wet-hulling method, also called Wet Hulling, is known locally as Giling Basah and is a traditional Indonesian coffee processing method. From the name alone, wet hulling seems very similar to wet processing (washed processing). However, the cupping flavors of these two processing methods are completely different. Coffee processed by wet hulling is usually full-bodied and intense, with a very distinct character.
In the 17th century, Dutch colonists first introduced coffee to Indonesia. These colonists sought more and faster economic returns. Wet-hulling greatly shortened the time spent on the farm and also greatly reduced labor costs. Front Street Coffee believes that the emergence of wet hulling coincided with the investor mentality of pursuing rapid profit and lowering costs. This is also one reason that drove the wet-hulling processing method.
Steps of the Wet-Hulling Process
① Remove the skin and pulp, retaining the parchment and mucilage
② Ferment in a water tank
③ Wash off the mucilage
④ Sun-dry with parchment for 2-3 days, to a moisture content of 20-24%
⑤ Remove the parchment
⑥ Dry the green beans to a moisture content of 12-13%
⑦ Prepare for export
The wet-hulling method creates Mandheling's special flavor. Front Street Coffee believes 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 will still be attempts with other processing methods. A Mandheling coffee recently introduced by Front Street Coffee uses the sun-dried processing method. This sun-dried Mandheling is very different in flavor from the Mandheling we know; this one leans toward fruit notes, with a sweeter mouthfeel and soft fruit acidity.
Front Street Coffee: Sumatra Wahana Estate Sun-Dried Mandheling
Coffee producing area: Lake Toba
Altitude: 1,000 to 1,700 meters
Soil: Volcanic soil
Coffee varieties: Bourbon, Typica
Processing method: Sun-dried processing
Harvest year: 2020
Grade: G1
Coffee Producing Area
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 and 1,500 meters and annual rainfall of 2,000 to 3,000 millimeters. 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 red cherries produced by Wahana all have a sugar content above 13%.
Wahana Estate is still a relatively young estate and 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 planting area as much as possible in the coming years. A large part of Wahana Estate is protected forest cover. This protected area includes many native plant and tree species around valleys and rivers. After that, coffee seedlings are planted in already divided planting areas and carefully marked for future variety identification.
The local seedling varieties currently planted include: Long Berry from Aceh, Toraja from Sulawesi, Rasuna from Sumatra, and S795 and dong Sari from Java. International nursery varieties include Costa Rica's Villa Sachi, Costa Rica's Caturra, Costa Rica's Catuai, and Colombia's Typica.
In order to produce high-quality North Sumatra coffee, Wahana Estate plants shade trees and uses organic fertilizer (compost) on the farm, practicing sustainable agriculture. 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.
Processing Method
The processing method of this bean is not Indonesia's unique wet-hulling method, but rather the more difficult sun-dried processing. The sun-dried process first requires manually selecting defective coffee beans, as well as unripe or overripe coffee cherries. After that, the coffee cherries are evenly spread out in a drying yard and need to be turned several times each day.
The drying process usually lasts about 2-3 weeks, depending on the local climate, and Indonesia's humid and rainy climate makes this time even longer. When the moisture content inside the coffee beans drops to 11-13%, the sun-drying step is complete. After drying, the outer shell of the coffee cherry has already become dry and hard, and it only needs to be hulled with a huller.
Brewing Suggestions
Wahana Estate Sun-Dried Mandheling coffee uses a light roast. It is recommended to use a V60 dripper, with a water temperature of about 90°C, a water-to-coffee ratio of 1:15, and a dose of 15g. The grind size should be finer than that for Lintong Mandheling, similar to granulated sugar (80% passing through China standard No. 20 sieve), in order to extract more of the coffee bean's flavor.
Front Street Coffee uses segmented extraction. Generally, the amount of water for blooming is twice the coffee grounds, that is, 30 grams of water for a 30-second bloom. Pour in a small stream in circles until 125 grams, then pause. When the water level drops and is about to expose the coffee bed, continue pouring until 225 grams and stop. The total extraction time is 2 minutes. Flavor description: It has a tropical fruit sweet-and-sour sensation on entry, with obvious fermented aroma, a smooth mouthfeel, tropical fruits, moderate acidity, and obvious sweetness.
V. Green Bean Comparison
If we carefully observe the green beans, we will find that Mandheling beans still have quite a few elephant-ear beans. This is caused by hulling the beans when their moisture content is relatively high and the bean texture is relatively soft.
Golden Mandheling: The mesh size is 19+, so it is noticeably larger than other Mandheling beans. Due to its higher moisture content, the green beans tend to be darker green;
Tiger Mandheling: The green beans are round and plump, slightly yellow with green, and have relatively good uniformity;
Lintong Mandheling: The green beans are grayish-green, and the green beans vary in size, relatively speaking not very uniform;
Aged Mandheling: Due to the processing method, the green bean color is quite special, orange with a dark tint, and the surface looks wrinkled, while the green bean size is also relatively uniform.
VI. Roasting Comparison
Front Street Coffee's roasting goal is to reflect the flavor of the coffee's producing area. Actually, each coffee bean can be roasted in any way, but Front Street Coffee believes that the roasted flavor should reflect the taste of that producing area. For example, Yirgacheffe should have the taste of Yirgacheffe, and then other possibilities can be developed on that basis. This is Front Street Coffee's only standard for determining coffee roasting.
1. Lintong Mandheling
Front Street Coffee's roasting goal for this bean is medium-dark roast, in order to erase excessive acidity and enhance its body and balance. The altitude of Lintong Mandheling is only moderate, and the bean texture is very soft. In order to remove excess moisture and avoid astringency and sourness caused by insufficient dehydration, a roasting technique of prolonging dehydration time and sliding down after reducing heat was adopted.
Bean drop temperature 200°C, turning point 5'18", first crack began at 9 minutes at 186°C, first crack development for 4 minutes, then out of the roaster at 202°C.
2. Golden Mandheling
Front Street Coffee believes that Golden Mandheling belongs to green beans with relatively high moisture, and compared with sun-dried beans there is a relatively high deviation in moisture, so special attention must be paid during dehydration. For green beans with high moisture content, after putting in the green beans, immediately close the air damper, steam for 30 seconds, then open to 3, until the color of the green beans turns light green or white, open the air damper to 4, and after first crack open to 5 (maximum).
Bean drop temperature 200°C, turning point 5'40", first crack began at 9'54'' at 191.2°C, first crack development 3'30'', then out of the roaster at 204.5°C.
3. Tiger Mandheling
Tiger Mandheling beans are round and plump, green with yellow, relatively uniform, and have higher moisture content. Front Street Coffee's roasting goal for this bean is medium-dark roast, in order to erase excessive acidity and enhance its body and balance.
During the roasting process, because the altitude of this bean is only moderate and the bean texture is very soft, in order to remove excess moisture and avoid astringency and sourness caused by insufficient dehydration, a roasting technique of prolonging dehydration time and sliding down after reducing heat was adopted. The heat was reduced separately when the beans reached the turning point, finished dehydration, and before first crack, to avoid scorching the bean surface. It was chosen to come out of the roaster 4 minutes after the end of first crack and 20 seconds before second crack, extending the caramelization reaction time and reflecting its excellent cleanliness and sweetness.
Bean drop temperature 200°C, turning point 5'18", first crack began at 9 minutes at 186.2°C, first crack development for 4 minutes, then out of the roaster at 203°C.
4. Aged Mandheling
Because Mandheling green beans have high density and aged beans have less moisture, heat adjustments at each stage must be made with special care. With Mandheling coffee, be careful not to scorch the oils on the surface of the original beans.
Bean drop temperature 200°C, turning point 5'35", first crack began at 9'30'' at 186.8°C, first crack development 3'20'', then out of the roaster at 197.5°C.
VII. Cupping Comparison
Lintong Mandheling: herbs, chocolate, caramel, overall relatively balanced;
Golden Mandheling: nuts, spices, herbs, licorice, chocolate, caramel, clean and soft flavor;
Tiger Mandheling: nuts, cream, dark chocolate, caramel, traditional Chinese medicine, obvious sweetness, relatively clean and clear flavor;
Aged Mandheling: ripe pu'er, caramel, herbs, chocolate, relatively low acidity.
VIII. How to Brew the Four Mandheling Coffee Beans by Pour-Over with a KONO Dripper
Front Street Coffee uses the pour-over brewing method, keeping the brewing parameters consistent to compare the flavors of the four Mandheling coffees.
For daily brewing of Mandheling, Front Street Coffee recommends using a KONO dripper, because the mouthfeel it brings out is rounder and fuller, and the flavor expression is more direct. The only exhaust part of the Kono dripper is that one-quarter of the ribs. When the water level passes over the rib area, the water level in the dripper keeps rising, increasing pressure through the weight of the water. Because the outlet is relatively small, it can extend the contact time between coffee particles and water a little longer. As the water flow drives it, soluble substances can be brought out more effectively. With this brewing method, Front Street Coffee can generally achieve the high-body effect expected by customers.
Front Street Coffee uses segmented extraction, using 30 grams of water for a 30-second bloom. Pour in a small stream in circles until 125 grams, then pause. When the water level drops and is about to expose the coffee bed, continue pouring until 225 grams and stop pouring. When the water level drops and is about to expose the coffee bed, remove the dripper. (Timing starts at the beginning of the bloom.) The extraction time is 2'00".
Brewed Flavors of the Four Mandheling Coffee Beans
Lintong Mandheling: herbs, chocolate, nuts, toasted bread
Golden Mandheling: spices, nuts, pine, chocolate, caramel
Aged Mandheling: ripe pu'er, chocolate, caramel, herbs
Tiger Mandheling: nuts, cream, dark chocolate, black sugar, caramel
For more specialty coffee beans, please add the private WeChat of Front Street Coffee. WeChat ID: kaixinguoguo0925
The above content is compiled by CoffeeHunters, a coffee news website.
