Why Pour-Over Indonesian Mandheling Coffee Tastes Sour - Golden Mandheling Coffee Bean Flavor and Taste Characteristics

There are always some coffee lovers who dislike sour flavors and are new to single-origin coffee. When they visit a café, they'll tell the barista: "I want a pour-over coffee that's not sour." At this point, the barista will typically recommend Mandheling coffee beans. After brewing and taking the first sip, the response is always bitterness, with some people even wanting to add sugar. I remember when FrontStreet Coffee first tasted Mandheling, what surprised me wasn't its bitterness but the herbal aroma before it entered my mouth, the burst of sweetness that exploded on my taste buds mid-palate, and the smoky sensation in the aftertaste. However, when I went to other cafés and ordered a Mandheling, something felt wrong with the first sip—Mandheling actually had a subtle sourness. Shouldn't Mandheling be bittersweet? Why does it have sourness? What should Mandheling actually taste like?

The Origin of the Mandheling Name

Mandheling's original name was Mandailing, which actually referred to a tribe in Indonesia. During World War II when Japan occupied Indonesia, a Japanese soldier went to a local café and tasted an incredibly aromatic cup of coffee. He asked the owner for the coffee's name, but the owner mistakenly thought the soldier was asking where he was from, so he replied: "Mandailing."

After the war, that Japanese soldier recalled the incredibly aromatic coffee he had in Indonesia. Through a friend's connection, he found a local coffee merchant in Indonesia to help him ship 15 tons to Japan. When others asked for the name, the Japanese soldier mistakenly said "Mandehling" instead of "Mandailing." Due to this "double misunderstanding," the term "Mandehling" was born. Because Mandheling coffee became extremely popular in Japan, the name Mandheling spread, and that coffee merchant was none other than the now-famous Pwani Coffee Company (PWN).

PWN Gold Mandheling

When it comes to Mandheling-flavored coffee, people often first think of "Gold Mandheling." This is an Indonesian Mandheling coffee bean. However, have you noticed that there are always some English letters mixed together with Mandheling coffee's name, such as FrontStreet Coffee's PWN Gold Mandheling.

In fact, PWN (Pwani Coffee Company) is the abbreviation for Pwani Coffee Company. This company is a very famous coffee acquisition company in Indonesia, mainly acquiring Indonesian Mandheling coffee beans, and almost all the best producing areas in Indonesia are acquired by them. Therefore, the Indonesian Mandheling coffee beans from PWN Company are mostly unique specialty beans. After buying back the beans, PWN Company will conduct multiple manual selections, picking out full, flawless beans, and only such beans will be classified as Gold Mandheling.

Later, PWN Company registered "Gold Mandheling" as a trademark. PWN Gold Mandheling became today's standard where only Gold Mandheling produced by this company can be considered true "Gold Mandheling." FrontStreet Coffee needs to emphasize that most PWN Gold Mandheling on the market today comes from the Aceh producing area of Sumatra.

Ateng

The coffee bean variety for FrontStreet Coffee's 2020 new harvest season Mandheling is Ateng, which is Catimor. Only Catimor grown in Sumatra and Indonesia's native islands can be called Ateng. Catimor is not the pure Arabica variety we often talk about, but rather a hybrid between Timor from the Robusta species and Catuai from the Bourbon variety.

It was initially developed in 1959 and began to be promoted in Brazil in the 1970s and 1980s. With its disease resistance and high yield, it secured a place among Central and South American coffee varieties. The occasional coffee leaf rust outbreaks in Central and South America also promoted the application of Catimor coffee beans. Compared to varieties like Typica and Bourbon, Catimor's characteristics are high yield, short plants that can be densely planted, and new leaves that are reddish-brown. However, due to fast maturation and high yield, it requires adequate fertilizer supply and shade, but according to FrontStreet Coffee's understanding, its lifespan is very short, averaging only ten years.

Wet-Hulling Process

When it comes to Indonesian Mandheling coffee, the impressive characteristics are the rich cocoa flavor upon entry and special herbal and earthy flavors. The reason for this special flavor is actually related to the processing method of Mandheling coffee.

Just as K72 is to Kenya and honey processing is to Costa Rica, wet-hulling can be said to be a very characteristic processing method in Indonesia. Due to the precious local water resources and unstable sun-drying conditions, locals combined Indonesia's rainy climate to invent the wet-hulling method.

The wet-hulling process is as follows:

1. Remove the coffee cherry pulp and place the parchment beans in large buckets or troughs filled with water, skimming off any defective parchment beans floating on the surface.

2. The dense parchment beans that sink to the bottom are slightly cleaned, taken out and placed in buckets or plastic bags for a brief dry fermentation, allowing the pectin sugars on the seed coat surface to ferment and enhance flavor. Basically, the longer the fermentation time, the heavier the acidity. The fermentation time varies by person, generally only a few short hours, but some estates skip the dry fermentation stage and directly sun-dry the parchment beans to suppress acidity and increase viscous mouthfeel, allowing the pectin sugars to fully ferment and enhance flavor. Usually, the fermentation time is between 12-36 hours, depending on specific conditions.

3. Sun-dry the parchment beans for one to two days until the bean moisture content reaches 30%-50%, while the beans are still half-hard and half-soft. Use a hulling machine to remove the parchment shell and continue drying, accelerating the drying process. About two days later, when the moisture content reaches 12%-13%, the coffee beans are collected into woven bags, usually 40kg and 80kg per bag, and sent to coffee processing plants for hulling. The process is completed in about four days.

4. The hulling process involves grinding off the bean husks with a hulling machine, then drying again until the moisture content reaches approximately 12%-15%. Then, the coffee beans are sent for machine sorting to remove various impurities and classified by particle size.

The wet-hulling method also results in defective beans such as moldy beans being much higher than in washed and natural processed coffees, because the fruit skin is removed during processing, allowing beans direct contact with air. It is precisely because of this that Mandheling has those special flavors of grass jelly, herbs, and earth.

Why Does Mandheling Have Sourness When It Should Be Bittersweet?

Actually, from the perspective of Mandheling green beans themselves, this is a coffee bean with extremely high acidity. Its characteristic acidity transformation is that under light-to-medium, medium, and medium-dark roasting levels, the fruit acidity will experience changes from quite obvious strong acidity to acidity to weak acidity.

FrontStreet Coffee once tried roasting FrontStreet Coffee's Gold Mandheling to light, medium, and dark roast levels to compare the differences, and found that regardless of whether it was light, medium, or dark roast, the flavor was not poor.

The reason why the Mandheling we commonly encounter is dark-roasted is twofold: first, due to its processing method and mixed varieties, this bean has a relatively high defect rate, and dark roasting can perfectly cover this defect; second, Mandheling was first discovered and promoted by the Japanese, who tend to prefer body-focused characteristics in coffee tasting. Therefore, it's not difficult to understand why Mandheling chooses dark roasting.

Coffee beans are the fruit of the coffee tree, and each fruit carries the natural characteristic of fruit acidity. The "acidity" in coffee is also affected by roasting and extraction. How the roaster roasts and how the barista brews will all affect the flavor of a cup of coffee. If you truly want Mandheling without any acidity, you might choose beans with a darker roast degree. After all, the longer the roasting time, the more floral and fruity acidic substances in the coffee have been eliminated; however, FrontStreet Coffee believes that fruit acidity can actually be an essential element in a cup of coffee, because it is these acidity levels that make the coffee's flavor layers become full, which also creates the unique personality of each cup of coffee.

FrontStreet Coffee: FrontStreet Coffee Gold Mandheling Coffee Beans

Company: PWN

Region: Gayo Mountain, Aceh, Sumatra

Altitude: 1100-1600m

Variety: Ateng

Processing Method: Wet-Hulling

Roasting Recommendations

When FrontStreet Coffee roasts FrontStreet Coffee Gold Mandheling coffee beans, the roast level is medium-dark, to eliminate excessive acidity in Mandheling and enhance its body and balance. FrontStreet Coffee Gold Mandheling belongs to green beans with relatively high moisture content, with a high deviation value from natural processed beans in moisture, so special attention must be paid during dehydration. FrontStreet Coffee recommends closing the damper immediately after adding the green beans, steaming for 30 seconds, then opening the damper to 3, until the green beans turn light green or white, then open the damper to 4, and open to maximum after first crack.

Machine: Yangjia 800N, green bean input 550g

Bean entry temperature: 200℃

Yellowing point: 5'40", 148℃

First crack point: 9'54", 191.2℃

3 minutes 30 seconds development after first crack, out at 204.5℃

Brewing Recommendations

FrontStreet Coffee recommends using freshly roasted coffee beans for brewing, which allows for the maximum appreciation of the coffee's rich flavors. The coffee beans shipped by FrontStreet Coffee are all roasted within 5 days, because FrontStreet Coffee deeply understands that the freshness of coffee beans greatly affects flavor. FrontStreet Coffee's roasting philosophy is "freshly roasted good coffee," ensuring that every customer who orders receives the freshest coffee when it arrives. The coffee's resting period is about 4-7 days, so when customers receive it, it's at its peak flavor.

Dripper: Kono dripper

Water temperature: 88℃

Dose: 15 grams

Ratio: 1:15

Grind size: Medium-fine grind (EK43s setting 11)

*Reason for choosing Kono dripper: The Kono dripper has few ribs located at the bottom, and the filter paper fits tightly against the dripper, which can restrict airflow and extend the contact time between water and coffee grounds, allowing the coffee grounds to be fully extracted and enhancing the rich body.

Brewing method: Segmented extraction

Use 30g of water for a 30-second bloom, then pour with a small circular flow to 125g for segmentation. When the water level drops and is about to expose the coffee bed, continue pouring to 225g and stop pouring. When the water level drops and is about to expose the coffee bed, remove the dripper. (Timing starts from the bloom) Extraction time is 2'00".

FrontStreet Coffee Mandheling flavor description: Multi-layered, rich and clean, high balance, with strong nutty and chocolate flavors, rich spice and caramel aromas, fruity notes, and persistent aftertaste.

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

For more specialty coffee beans, please add FrontStreet Coffee's private WeChat account: kaixinguoguo0925

Important Notice :

前街咖啡 FrontStreet Coffee has moved to new addredd:

FrontStreet Coffee Address: 315,Donghua East Road,GuangZhou

Tel:020 38364473