Where Did the Herbal Flavors of Indonesian Mandheling Coffee Go? How to Handle Off-Flavors When Brewing Pour-Over Mandheling Coffee

For more premium coffee knowledge, please follow the WeChat official account: FrontStreet Coffee

The Divisive Nature of Mandheling Coffee

Mandheling is a highly polarizing coffee bean. Those who love it become intoxicated by its wild spice aromas, herbal fragrances, caramel and cocoa notes, and its unparalleled thick mouthfeel. Those who dislike it find it bitter and burnt, with mixed notes of herbal medicine, earthy flavors, and woody tastes.

Often, when describing the flavor characteristics of Mandheling, people mention its distinctive "herbal" and "earthy" notes. However, today's Mandheling has gradually lost these herbal flavors—at least, compared to Mandheling from a few years ago, that unique taste has become less pronounced.

To explore how Mandheling's special herbal flavor came to be, we must examine the local growing environment, varieties, and processing methods.

Origin and Growing Regions

Mandheling coffee refers to Arabica coffee beans grown on the island of Sumatra. The main producing areas are near Lake Toba and Lake Tawar, with Lake Toba being famous for the Lintong region and Lake Tawar for the Gayo Mountain region. The altitude here ranges from 1,100 to 1,600 meters, which is ideal for growing quality coffee. In the early 18th century, the Dutch expanded coffee plantations to Sumatra, giving this land a long history of coffee cultivation.

Varietal Characteristics

The varieties might be the reason why Indonesian coffee has herbal and earthy flavor characteristics. In the 18th century, the Dutch planted varieties like Typica and Bourbon on the island. Later, during the devastating leaf rust epidemic of 1876, Indonesian authorities had to introduce new varieties from around the world to preserve coffee production. Since then, Indonesian land has become a melting pot of coffee varieties.

Common coffee varieties found in Sumatra today include Ateng (local Catimor), TimTim (local Tim), Typica, Catuai, and Robusta. The main varieties of Mandheling, Ateng and TimTim, contain Robusta genes, which contribute to some grassy and earthy flavors.

Wet Hulling Processing Method

However, what most people consider the source of Mandheling's herbal flavor is the local unique wet hulling processing method. The reason for using wet hulling is that Sumatra has consistently high humidity throughout the year, with unpredictable weather alternating between sunny and rainy. Wet hulling is used to shorten drying time and preserve the quality of coffee beans.

The wet hulling process is roughly as follows: first, a pulping machine removes the outer skin and pulp from the coffee cherries, then the coffee beans are washed. If the weather is good, drying for just 3-4 days will reduce the moisture content of the coffee beans to about 30-40%. At this point, the coffee beans are in a semi-soft state. A hulling machine is then used to remove the parchment from the bean surface, and after a few more days of drying, they can reach 12-13% moisture. If natural processing were used, it might take 3 weeks.

The herbal and earthy flavors might come from the rough drying process (due to simple equipment, the drying method involves spreading beans directly on cement floors or compacted dirt roads. After removing the protective parchment, the high humidity environment can easily contaminate the coffee beans).

The Evolution of Mandheling Flavors

So why is Mandheling's herbal flavor becoming increasingly weak? Among so many Mandhelings, Golden Mandheling has almost no herbal or earthy flavors, instead showing a mellow, clean, and bright taste.

Golden Mandheling is a product from the green bean company Pawani, which registered the trademark in 2003. Pawani does not participate in cultivation; it only visits various producing regions to find the best coffee beans in Indonesia. Currently, Pawani's Golden Mandheling comes from Gayo Mountain in Aceh. Similarly, this Golden Mandheling variety is Ateng, which also contains Robusta genes, but it doesn't have the earthy flavor typical of Catimor. Therefore, some experts believe that Ateng has adapted to Indonesian terroir, while others think Ateng is a backcross of Catimor and Typica, which further dilutes the Robusta genes.

In terms of processing methods, although they're all called wet hulling, there can be significant differences in actual operation. For example, if coffee beans have their parchment removed at different moisture levels, would the flavor differ? If more care is taken during drying—keeping the beans away from the ground, turning them frequently to ensure even drying—could this reduce earthy and herbal flavors? The detailed processing process is unknown, but FrontStreet Coffee can see different performances in the green beans.

In 2018, the "horseshoe bean" characteristic of Golden Mandheling was quite obvious, but starting from 2020, the "horseshoe beans" in Golden Mandheling became fewer. This should be due to improvements in the processing workflow.

Golden Mandheling is also priced significantly higher than other Mandhelings because Pawani conducts three rounds of manual selection after purchasing the green beans, removing defective, small-sized, and unattractive beans. What remains are large, full beans with few defects. This practice improves the cleanliness of the coffee.

FrontStreet Coffee previously had a coffee called Tiger Mandheling, which had a very rich traditional Chinese medicine aroma that appealed to some friends' taste buds. Occasionally, some customers would ask if this bean was still available. FrontStreet Coffee chose to stock it precisely because of this special aroma. However, in recent years, the Tiger Mandheling's traditional Chinese medicine fragrance is no longer as rich as before.

Changing Perceptions of Indonesian Coffee

Herbal, spicy, wild, and mellow flavors—perhaps this is one generation's impression of Mandheling, and even Indonesian coffee as a whole. However, in Indonesia's first COE competition in 2021, Indonesians showed the world through action that Indonesian coffee has more than just the stereotypical herbal flavors—it also has high-sweetness fruits and overflowing floral aromas.

Important Notice :

前街咖啡 FrontStreet Coffee has moved to new addredd:

FrontStreet Coffee Address: 315,Donghua East Road,GuangZhou

Tel:020 38364473