How does wet hulling shape Mandheling coffee quality?

Sumatra is the birthplace of Mandheling coffee. Its wet-hulling process, combined with local terroir, produces the herbal spice aroma and heavy, full body the coffee is known for. Among the many Mandheling lots, Golden Mandheling from PWN stands apart because of strict hand sorting and cleanliness. PWN has trademarked the English name, so only its beans can properly carry the name.

Front Street keeps two Indonesian Mandheling coffees, and the PWN Golden Mandheling has gone through three rounds of hand sorting, which lowers the defect rate and lifts sweetness and clarity. Authentic bags show the PWN logo, a certificate of origin, and the words Triple pick and Grade 1. A medium-dark roast and steady pouring bring out the herbal notes. The right coffee description words help buyers recognize these traits.

Sumatra is the birthplace of Mandheling coffee, and its unique terroir and wet-hulling process have shaped this coffee's signature herbal spice aroma and rich, full-bodied taste. Among the many Mandheling products, the Golden Mandheling produced by PWN stands out thanks to strict hand-sorting standards and cleanliness, becoming a representative of Indonesian specialty coffee. Front Street Coffee regularly offers two Indonesian Mandheling coffees, among which PWN Golden Mandheling has undergone three rounds of hand sorting, with an extremely low defect rate and superior sweetness and cleanliness. This article will take you deeper into the Sumatra producing region, the secrets of the wet-hulling process, and the unique charm of Golden Mandheling, and share Front Street's medium-dark roast brewing parameters.

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An exclusive brand under PWN Green Coffee Company, it gives Mandheling the name "Golden," making it a fairly representative presence in Indonesian specialty coffee. In this article, Front Street will discuss what exactly makes Front Street PWN Golden Mandheling coffee so distinctive.

Authentic Golden Mandheling Coffee

Front Street's regular bean list always includes two Indonesian Mandheling coffees for everyone to choose from, and the most popular is undoubtedly the "Front Street PWN Golden Mandheling Coffee," which has undergone layer upon layer of manual selection. It retains Mandheling's signature herbal spice aroma and mellow taste, while also reducing the off-flavors commonly found in Indonesian coffee because the defect rate is greatly lowered, bringing cleanliness to an even higher level.

"Golden Mandheling" is an exclusive brand of Pwani Coffee Company (PWN). There are all kinds of Mandheling products on the market, but PWN has registered the English name "Golden Mandheling" as a trademark, so only Golden Mandheling produced by PWN can truly be called Golden Mandheling in the real sense. To identify authentic Golden Mandheling, you can look for the green bean jute bags bearing the PWN logo and the certificate of origin signed by PWN. Front Street displays these two identifiers in its Dongshankou store.

If you observe the jute bags of Golden Mandheling green beans, they are printed with the words "Triple pick" and "GRADE 1," indicating that it belongs to Indonesia's highest grade of green beans. After purchasing GRADE 1 green beans, PWN then carried out three rounds of manual hand sorting.

The grading of Indonesian green coffee beans is mainly based on the number of defective beans, with bean size as a secondary reference. Basic quality requirements include: no live insects, no moldy or rotten-smelling beans, maximum moisture content of 12.5%, and impurity rate below 0.5%. According to defect rate, it is divided into six grades, and the highest grade, G1, requires fewer than 11 total defective beans in a 300g sample. The Lintong Mandheling coffee in Front Street's daily drinking series is G1, produced in the Lintong region of Sumatra and processed using the wet-hulled method, presenting the classic Indonesian Mandheling flavor: dark chocolate, nuts, herbal spices, and caramel.

PWN takes the screening process to the extreme, subjecting G1-grade Mandheling to multiple strict selections, pressing the defect rate to the lowest possible level, removing off-flavors such as earthiness, and at the same time enhancing Mandheling's sweetness and cleanliness. In addition, before packaging, PWN also sends the green beans through a machine for density and color sorting to ensure that the Golden Mandheling green beans it produces are large, uniform, and bright in color.

Mandheling is also called Sumatra coffee

Coffee, like various vegetables and fruits, is an agricultural product, and its flavor is always closely related to factors such as variety, climate, altitude, soil, and management. It is a true reflection of the variety and local terroir. Post-processing methods and roasting should maximize the preservation, restoration, and expression of its most authentic flavor. Mandheling's distinctive flavor is inseparable from the mysterious island of Sumatra.

Sumatra is divided into eight provinces in total, but only the high-altitude provinces of Aceh and North Sumatra cultivate Arabica coffee on a large scale. Sumatra belongs to a tropical rainforest region, and the mountains and forests are shrouded in clouds and mist all year round, casting a mysterious veil over this island. Local people plant coffee trees around two major volcanic lakes—Lake Tawar and Lake Toba. The Gayo Mountains around Lake Tawar have ideal conditions for coffee cultivation and widely adopt organic farming methods. Coupled with a long history of cultivation, the coffee produced here is higher in both quality and yield, so many green bean merchants place special importance on this area, including the locally renowned Pwani Coffee Company (PWN).

Semi-washed method—wet-hulled method

Friends who often drink Mandheling are certainly familiar with the wet-hulled method. The processing time for the wet-hulled method is much shorter than that of the washed method. Traditional washing takes 1 to 3 weeks, while the wet-hulled method can complete the entire process in just a few days. The wet-hulled method first removes the skin and pulp of the coffee fruit, then after a short fermentation it is dried, and in a semi-dry state the parchment layer is removed, after which drying continues in the later stage. When the moisture content reaches 12%, it can be bagged, sorted, and graded.

Although the wet-hulled process seems fast and time-saving, without strict control it is highly prone to moisture and mold in Indonesia's hot and humid environment. But besides Sumatra, Sulawesi in Indonesia and Papua New Guinea also widely use this processing method. This is because Indonesia has a tropical rainforest climate, with air humidity as high as 70–90%, making it impossible to dry green coffee beans through long periods of sun exposure, while the cost of washed processing is relatively high. Left with no choice, coffee farmers developed this semi-washed processing method. Although the time required for each step is greatly shortened, the green beans after removing the parchment layer still absorb moisture from the hot and humid air, so the resulting Mandheling coffee carries a somewhat woody, herbal, spicy, muted aroma.

In order to present the classic Mandheling flavor, Front Street uses a medium-dark roast to erase too much of Mandheling's acidity and enhance its body and balance. During cupping, Front Street perceived that Golden Mandheling has the aromas of spices, herbs, and pine wood, the rich, mellow bittersweet flavors of caramel, nuts, and pure dark chocolate, as well as the delicate sweet aftertaste of fruit and melon, with multiple layers, rich and clean, and a high degree of balance.

Flavor characteristics of medium-dark roasted Golden Mandheling coffee

Front Street's flavor descriptions for every coffee are based on freshly roasted beans. If coffee beans are stored for more than a month, part of the aroma has likely already been lost, and it is very difficult to reproduce it in brewing. Front Street deeply understands the importance of freshness, so it ensures that only coffee beans freshly roasted within 5 days are shipped, allowing everyone to enjoy the fullest flavor window upon receipt.

When brewing medium-dark roasted coffee beans, Front Street uses brewing parameters different from those for light-roasted coffee beans, so that the coffee presents a richer chocolate character. Medium-dark roasting undergoes more caramelization than light roasting, so it more easily releases bitter large-molecule substances. To avoid extracting too many off-flavors, Front Street appropriately lowers the water temperature. The brewing water temperature for light-roasted coffee is 91–93°C, while for medium-dark roasted coffee beans Front Street recommends 87–88°C.

The grind size is also made a bit coarser, paired with a Kono dripper for staged extraction. The Kono dripper has few ribs and they are located at the lower end. The filter paper fits tightly against the dripper, which can restrict airflow and lengthen the contact time between water and coffee grounds, allowing the coffee grounds to be fully extracted and enhancing the mellow taste.

Dripper: Kono dripper Water temperature: 88°C Dose: 15g Coffee-to-water ratio: 1:15 Grind size: 70-75% passing through a No. 20 standard sieve

Front Street uses staged extraction, blooming with 30g of water for 30 seconds, then pouring in a small stream in a circular motion until 125g for the stage break. When the water level is about to expose the coffee bed, continue pouring until 225g and then stop. When the water level is about to expose the coffee bed again, remove the dripper. The extraction time (starting from the beginning of blooming) is 2'00".

The above content is compiled by CoffeeHunters, a coffee news website.