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What Are Aged Coffee Beans and the Characteristics of Sumatra Aged Mandheling Coffee

Published: 2026-01-27 Author: FrontStreet Coffee

Last Updated: 2026/01/27, Aged coffee beans processing method: Aged coffee beans do not refer to simply storing coffee beans for a long time, as this is not recommended. Coffee beans that are stored for too long will deteriorate, changing from fresh green to white, then to yellow, losing all flavor and aroma.

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Aged Bean Processing Method

Aged coffee beans do not refer to coffee beans that have been left around for a long time. This is not acceptable because coffee beans will still deteriorate over time, changing from fresh green to white, then to yellow, becoming tasteless, and even growing insects. Just like aged wines, green beans must undergo proper processing and long-term storage before they can be called truly "aged coffee."

The most famous coffee-producing regions in Asia are the various islands of the Malay Archipelago: Sumatra, Java, and Kalimantan. Among these, the Mandheling coffee from Sumatra, Indonesia, is particularly renowned. It has two famous varieties: Sumatra Mandheling DP Grade 1 and Classic Sumatra Mandheling. Sumatra Mandheling DP Grade 1 has a long aftertaste with a wild, mountainous fragrance - that unique earthy flavor found in primeval forests. Actually, the richness of Mandheling has a very masculine quality.

Premium Grade 1 Mandheling coffee has very light acidity, like the subtle tartness of flowers and fruits. Besides the characteristic richness of Indonesian coffee, it also has a bitter-sweet flavor that is deeply loved by those who enjoy dark roast coffee; Classic Sumatra Mandheling coffee is called "Classic" because it is stored in cellars for three years before export. However, classic coffee is not stale coffee, but rather specially processed slightly pale coffee. This coffee is more intense, with reduced acidity but increased body, a longer aftertaste, and carries strong spice flavors - sometimes tangy, sometimes walnut, sometimes chocolate. Before Blue Mountain coffee was discovered, Mandheling was considered the finest among coffees. A very interesting point is that although Indonesia produces the world's most mellow coffee, Indonesians prefer Turkish-style coffee.

Indonesia's Sumatran islands produce coffee due to their unique geographical location, climate, and latitude/longitude, making them abundant in coffee production. Indonesian coffee has high body, weak acidity, and strong aroma. The more famous region is the Lintong area. Mandheling is also representative of Indonesian coffee, and it's worth mentioning that some coffee enthusiasts enjoy what's called "Mamba coffee," which is a blend of Mandheling and Brazilian coffee.

The main producing areas include Sumatra Island, Java Island, and Sulawesi Island. Among these, 90% are Robusta varieties, considered first-class in quality. Sumatra Island is famous for its rich, smooth, and highest-grade "Mandheling." Additionally, "Gayo Mountain" is produced in the northern part of the island, while Java Island's "Java Arabica" has good acidity and is especially loved by the Dutch. Sulawesi Island produces large-grained "Kalossi," with "Toraja" from the mountainous region in the southwest (elevation 1200 meters) being representative.

Aged Mandheling

The fruity acidity of Mandheling, after long-term aging, not only becomes gentle and smooth, but its body and unique flavors can also be impressively expressed in the mouth - this is the charm of Aged Mandheling. Coffee farmers select high-quality green beans and then subject them to strict monitoring standards for up to 24 months of static aging. During the waiting period, they regularly turn the green beans in the storage tanks to prevent moisture and mold. This process is extremely labor-intensive and creates this more fragrant and long-lasting Aged Mandheling.

FrontStreet Coffee's tips for Aged Mandheling~

FrontStreet Coffee recommends roasting Aged Mandheling to medium-dark roast to eliminate the bean's fruity acidity and highlight the caramel sweetness as well as cocoa and nutty flavors of Aged Mandheling. For brewing, FrontStreet Coffee recommends using a KONO dripper or a conical three-hole dripper for extraction. The immersion extraction method can perfectly express the bean's rich body and caramel sweetness with balanced flavors. As for brewing water temperature, since Aged Mandheling is a medium-dark roasted bean, FrontStreet Coffee recommends using lower water temperature, specifically 86-88°C for brewing; the coffee can be ground slightly coarser, i.e., medium grind, to reduce over-extraction during brewing; for the coffee-to-water ratio, FrontStreet Coffee recommends choosing a smaller ratio of 1:13-1:14, which can better highlight the rich, full-bodied character of Aged Mandheling.