The Origin and History of Aged Coffee: The Invention, Processing Methods, and Flavor Characteristics of Aged Mandheling

Most of the time, we emphasize the importance of fresh coffee, highlighting the differences between new crop coffee beans and old crop beans to make everyone realize they should drink fresh coffee. However, there's one exception: aged Mandheling. What makes it so special that it attracts coffee enthusiasts with its "expired" reputation?

What is Aged Mandheling?

It could be said that this was the result of an "accident." This story dates back to the Dutch colonial period in Indonesia, when Sumatra was one of the world's major coffee-producing regions. The coffee produced had to supply the huge demand of European consumer countries. Indonesia had to continuously transport coffee beans to Europe. To ensure a constant supply, coffee beans were stored appropriately. However, due to external factors such as long transportation distances and exposure to sea breezes, the coffee beans developed a unique special flavor by the time they reached Europe, captivating European coffee connoisseurs.

Therefore, people discovered that by aging processed coffee beans for several years, the acidity gradually disappears, leaving behind solid aftertaste and sweet notes, with a flavor as captivating as Pu-erh tea. However, we can't use "accidental" methods to produce aged beans, as this undoubtedly adds uncertain risks to coffee quality. We must clarify one point: "aged beans" are not simply coffee beans left in a warehouse for several years, because beans stored for too long can spoil, even developing mold or insect damage. These wouldn't be "aged beans" but rather bad beans. Therefore, the production model for aged Mandheling gradually became standardized and mature.

Aging Process for Mandheling

First, freshly harvested coffee cherries must undergo regular processing. For example, FrontStreet Coffee's aged Mandheling coffee beans are processed using the wet-hulling method. In this process, it's necessary to carefully select good beans (plump, large screen size, defect-free) for aging. After selecting the coffee beans, they are stored in warehouses for aging.

The aging process must be conducted in the origin country, stored in warehouses with temperature and humidity control or good ventilation. During aging, the beans must be regularly turned and checked for two purposes: first, to ensure even exposure to air and consistent moisture content; second, to check for moldy or insect-damaged beans to prevent widespread infection.

Today's aged Mandheling typically ages for 2-3 years, during which the acidity of the coffee beans gradually diminishes and converts to sugars, and the color becomes deeper, mostly yellowish-brown or dark brown, making it quite distinctive.

What is Golden Mandheling?

The fame of Mandheling coffee originated when the Pwani Coffee Company (PWN) successfully launched Mandheling in the Japanese market. Unlike many local green bean suppliers in Indonesia, PWN Company is an exclusive supplier of high-grade Golden Mandheling coffee, contracting the best Mandheling coffee-producing regions in Indonesia, where the produced Mandheling beans are all superior quality.

The wet-hulling method saves much time and labor costs for green bean processing, but the rapid process also brings higher defect rates. Therefore, only through strict manual selection can defects that machines cannot screen out be removed. PWN Company subjects purchased Mandheling green beans to one machine selection plus three manual selections, with quality far exceeding Indonesia's local highest G1 grade. To meet PWN's Golden Mandheling production standards, several requirements must be satisfied:

1. Green bean screen size: 18-19 screen or above after first manual selection
2. Fewer than 3 defective beans in a 300-gram green bean sample
3. Green coffee bean grade must be G1 level
4. Dark green color, uniform size, and neat shape

Before launching any coffee bean, FrontStreet Coffee conducts cupping to appreciate the coffee. Cupping is an evaluation of coffee bean quality and flavor, using unified standards to more objectively identify the strengths and weaknesses of the flavors presented by the beans, as well as their characteristics. Through cupping, FrontStreet Coffee found that Lindong Mandheling daily beans present rich nutty notes, with a hint of melon aroma in the later stages, and herbal plant flavors emerge as the temperature drops, with a mellow mouthfeel and saturated aroma. PWN Golden Mandheling not only has aromas of dark chocolate, nuts, and caramel, but also herbal spice and pine flavors, with dark chocolate aftertaste, ample lingering notes, high cleanliness, and light fruit acidity as the temperature decreases.

Pour-over Parameters for Mandheling Coffee

Brewing water temperature: 87-88°C
Coffee grounds: 15 grams
Grounds-to-water ratio: 1:15
Dripper: KONO dripper
Grind size: Medium-coarse (Chinese standard 70% pass-through rate on #20 sieve)
Brewing method: Three-stage pouring

Dark roasting makes the internal texture of coffee beans loose, easily crushable with a gentle pinch, indicating that the bean structure has been significantly altered. After grinding, the powder becomes highly absorbent. To avoid over-extraction of coffee grounds after water absorption, which would release large amounts of bitter substances, FrontStreet Coffee uses a coarser grind than for light roast coffee beans. Here, medium-coarse grinding is used (Chinese standard 70% pass-through rate on #20 sieve), with EK43s setting 11 in-store.

Roasting promotes caramelization and Maillard reactions in coffee beans. As the roast level deepens, more non-enzymatic browning occurs from the interaction and decomposition of monosaccharides and amino acids under heating, making it easier to release bitter, large-molecule substances. To avoid extracting too many undesirable flavors, FrontStreet Coffee reduces the water temperature slightly. The brewing water temperature for light roast coffee is 91-93°C, while FrontStreet Coffee recommends 87-88°C for dark roast coffee beans.

For coffees with rich mouthfeel like Indonesian Mandheling, Brazilian Queen Estate coffee, and Jamaican Blue Mountain coffee, FrontStreet Coffee baristas prioritize using KONO drippers for brewing.

FrontStreet Coffee baristas consistently use the three-stage pouring method, dividing water injection into three stages to better express the rich mouthfeel and caramel sweetness of Golden Mandheling coffee, while also providing greater control over time and water volume.

Wet the KONO dripper to ensure the filter paper fits snugly against the coffee dripper. After pouring out the water from the sharing pot, add 15g of ground coffee, bloom with 30g of water for 30 seconds. This water injection completely wets the coffee grounds for degassing, allowing for better extraction of flavor compounds in subsequent steps.

Some friends extend the bloom time to 45 or 50 seconds when extracting light roast coffee beans to enhance the front-end aroma. However, for dark roast Mandheling coffee, if the bloom time is too long, it can easily release excessive woody and undesirable flavors. Therefore, FrontStreet Coffee chooses a 30-second bloom.

In the second stage, start from the center and slowly pour hot water in small circular motions until reaching 125g, then pause. The water flow must be steady throughout. Overly vigorous stirring can easily break apart the coffee grounds wall, leading to uneven extraction.

Wait until the coffee grounds layer drops to half the dripper's height, exposing the coffee bed, then begin the second stage using the same technique until reaching 225g. Once all dripping is complete, remove the dripper. Extraction time is two minutes, with a 10-second margin of error.

Finally, gently shake the coffee in the lower pot and begin enjoying the pour-over Golden Mandheling black coffee. The brewed Mandheling coffee presents aromas of spices, dark chocolate, nuts, caramel, and pine, with a mellow yet clean mouthfeel, noticeable aftertaste, and persistent lingering notes.

Important Notice :

前街咖啡 FrontStreet Coffee has moved to new addredd:

FrontStreet Coffee Address: 315,Donghua East Road,GuangZhou

Tel:020 38364473