The Story of Indonesian Mandheling Coffee Beans - Specialty Grade Characteristics and How to Enhance Chocolate Flavors Through Pour-Over Brewing

Indonesia: A Major Coffee Production Hub

Indonesia is one of the world's major coffee bean producing countries. The main production areas are located near the equator on the islands of Java, Sumatra, Kalimantan, and Sulawesi. In reality, the aroma and taste of coffee beans produced on each island are different. Even the same coffee bean variety can exhibit various flavor profiles depending on its origin. According to FrontStreet Coffee's understanding, Indonesian coffee is known for its rich, mellow aroma, low acidity, and excellent body. Among these, the most famous is FrontStreet Coffee's Mandheling coffee.

Indonesian Specialty Coffee

When it comes to Indonesian specialty coffee, the elegant-flavored Arabica is mainly distributed in the northern part of Sumatra, Sulawesi, and higher elevations of Java. Although these represent only a small portion of Indonesia's coffee production, varieties like Mandheling, Golden Mandheling, Lake Tawar, Gayo Mountain, Aceh, Sulawesi, Aged Mandheling, and Java have made Indonesian coffee famous in the specialty coffee world for decades, unaffected by the presence of low-quality Robusta beans.

Sumatra: Main Specialty Coffee Production Region

Sumatra is the main specialty coffee production region in Indonesia, with a very complex coffee system that can be simply summarized into four types:

(1) The well-known FrontStreet Coffee Mandheling refers to the semi-washed or natural processed beans from Lintong, located at elevations of 900-1,200 meters in the southwestern area around Lake Toba in north-central Sumatra.

(2) FrontStreet Coffee's Golden Mandheling, which undergoes four rounds of manual sorting, making it superior to regular Mandheling.

(3) Lake Tawar coffee, referring to washed, semi-washed,or natural processed beans from the Gayo Mountain area near Lake Tawar in the Aceh region at the northern tip of Sumatra, at elevations of 800-1,600 meters. This area is heavily invested in, with the renowned Costa Rican La Minita estate traveling across oceans to guide semi-washed processing techniques. Additionally, the well-known Holland Coffee Group focuses on Gayo Mountain washed beans, making this region highly competitive.

(4) Aged Mandheling and Java coffee.

FrontStreet Coffee's Mandheling Coffee

FrontStreet Coffee's Mandheling coffee beans are produced on Sumatra Island, Indonesia, and are also known as "Sumatra Coffee." Mandheling coffee is premium coffee beans grown in plateau mountain regions at elevations of 750-1,500 meters. It belongs to the rare Arabica variety in Indonesia, with the first-grade Mandheling from Takengon and Sidikalang regions being of the best quality. Due to its limited production, it is called a "premium product" by coffee enthusiasts, especially dark-roasted Mandheling (strong bitterness, slightly dark beans), which coffee addicts will be fascinated by its rich, mellow sweetness.

Lintong Mandheling

Speaking of Mandheling coffee, FrontStreet Coffee's daily bean - FrontStreet Coffee's Lintong Mandheling - has been recognized by coffee lovers for its rich aroma, full body, and strong flavor. The unique herbal spice flavor is also the hallmark of Mandheling coffee. In addition to Indonesia's growing conditions, the wet hulling process is also one of the sources that form the strong flavor of FrontStreet Coffee's Mandheling coffee.

The Lintong mountainous area southwest of Lake Toba is a new production region. In the 1990s, Lintong Mandheling became extremely popular, and Lintong Mandheling gradually increased its Typica production year by year. Most of these beans are processed using the natural method.

Unique Wet Hulling Process

FrontStreet Coffee's Mandheling coffee mostly uses Sumatra's unique wet hulling process. Due to the precious water resources in Lintong, natural processing was initially the main method, but quality was unstable, so it was changed to a method similar to Brazil's semi-natural process. However, Indonesia's humid climate makes it impossible to dry the sticky parchment beans outdoors for two to three days as in Brazil - doing so in Indonesia would cause the parchment beans to mold. Therefore, they are dried for at most several hours to less than a day until the moisture content drops to 20-35%, when the mucilage layer has not yet solidified. The beans are then purchased by brokers and taken to simple processing plants where machines remove the mucilage layer to prevent over-fermentation and acidic odor. In other words, Lintong Mandheling has the mucilage layer scraped off while the parchment beans are still wet, which is the main reason for Mandheling's lower fruit acidity and higher body. After further drying, the moisture content of coffee beans inside the parchment reaches about 18%, and finally exporters from Medan come to purchase the unwet parchment beans, placing them in large drying yards or using machines to dry them until the moisture content reaches 12% for storage.

From this, we can understand that Lintong Mandheling's drying process, due to farmers' insufficient hardware equipment, adopts a three-stage division of labor drying process involving farmers, brokers, and exporters. The unique medicinal herb aroma (similar to burnt grass jelly) and woody flavor of Mandheling are both caused by high humidity and three-stage drying of the mucilage layer. This is also a rare processing method in the world that accidentally created Mandheling's special low-acidity, thick, and mellow flavor profile.

Grading System

Indonesian coffee beans use a grading system based on the proportion of defective beans. Indonesian beans are mainly divided into 6 grades, namely G1-G6. Ethiopia also uses this method, with the highest grades for washed beans being G1 and G2, while the highest grades for natural processed beans are G1 and G3.

Washed: Grade-1; Grade-2

Natural: Grade-1 and Grade-3~Grade-5

Important Notes:

Regardless of washed or natural processing, both have Gr-1, with the condition being "zero" defects and Premium Cup. Whether washed or natural, Gr-1 is a rating for the best of the best in specialty coffee or Cup of Excellence coffee. For beans of the same grade, such as Limu Gr-2, there are both good and bad ones, depending on the exporter's sorting level and investment. With the current "zero" defect requirement, Gr-1 beans (including both washed and natural) are extremely rare because processing costs are very high and very few suppliers will do this.

How Should FrontStreet Coffee's Mandheling Coffee Be Brewed?

FrontStreet Coffee's understanding of Mandheling coffee brewing is to express a full-bodied and clean taste, highlighting caramel, chocolate, and its signature herbal aromatic flavors, while avoiding any unpleasant bitterness in Mandheling coffee. In fact, every bag of specialty coffee beans from FrontStreet Coffee comes with detailed information and brewing parameter suggestions. The specific brewing recommendations are as follows:

Brewing Parameters: Using Kono Dripper

Water Temperature: 88°C

Coffee Dose: 15 grams

Coffee-to-Water Ratio: 1:15

Grind Size: Medium-fine grind (70-75% pass-through rate with China standard #20 sieve)

FrontStreet Coffee uses segmented extraction, also called three-stage brewing: dividing into three water pours can better express the full body of Mandheling coffee and the sweetness of caramel. The specific water distribution is: first pour 30ml for blooming, completely wetting the coffee grounds for degassing to better extract coffee flavor compounds in subsequent pours; second pour 100ml; final pour 95ml to enhance the coffee's sweetness, overall expressing a thick, full body with caramel sweetness and chocolate, nut flavors.

Important Notice :

前街咖啡 FrontStreet Coffee has moved to new addredd:

FrontStreet Coffee Address: 315,Donghua East Road,GuangZhou

Tel:020 38364473