Flavor Profile and Texture Characteristics of Pour-Over Dark Roast Coffee: An Introduction to Bitter Coffee Flavor Descriptions

Coffee flavor profiles emerged alongside the concept of specialty coffee. Nowadays, when taking a sip of lightly roasted coffee, many people can effortlessly describe several flavor notes. The most skilled among them can even recite coffee flavors with the same fluidity as reading a menu.

However, when it comes to dark roasted coffee, describing flavors becomes somewhat challenging. Often, words fail to adequately express the experience. "Nutty" and "chocolate" seem to have become representative flavor descriptors for bitter coffee, while "mellow" has become the highest praise for such brews.

Tasting the Flavors of Bitter Coffee

In past flavor tasting shares, FrontStreet Coffee has rarely provided detailed introductions to the flavor characteristics of bitter coffee. Therefore, this issue focuses on sharing how to taste the flavors of bitter coffee.

Bitter flavors, just like acidic ones in coffee, are composed of both aroma and taste. Therefore, when tasting bitter-toned coffee, we shouldn't rely solely on our tongues but also combine the aromas detected by our noses. Most bitter flavors in coffee are formed through caramelization reactions and Maillard reactions during roasting. The deeper these reactions occur, the more pronounced the bitter flavors become.

Categories of Bitter Coffee Flavors

The first category of flavor is caramel, the most prominent flavor produced by caramelization reactions. Caramelization begins after the first crack, when this reaction browns sugar compounds, producing caramel and maple syrup aromas. Often, when referring to caramel and maple notes, it's not about the sweetness on the palate but rather the similarity in the coffee's aroma. Therefore, please don't compare the caramel and maple flavors in coffee to the sweetness of actual caramel syrup or maple syrup.

The second flavor category is roasted taste, similar to the aroma emitted by toasted bread or roasted meat. This roasting aroma is produced by Maillard reactions between amino acids and proteins within the coffee beans, which is precisely what we often refer to as "coffee aroma."

The third flavor category is nutty and chocolate notes. Nuts and chocolate are the most easily identifiable flavors in bitter coffee. They are also catalyzed by Maillard reactions between amino acids, proteins, and other compounds. Like citrus, nuts are also a general category that can be further subdivided into flavors such as roasted almonds, roasted peanuts, and roasted hazelnuts. Chocolate typically refers to dark chocolate, with a bittersweet taste that differs significantly from the high-cocoa-butter substitute chocolates commonly consumed.

The fourth flavor category is spiced notes, also catalyzed by Maillard reactions, which can include flavors such as clove, cardamom, and cinnamon in coffee. However, these flavors tend to be more difficult for us to identify. This is because these spices rarely appear alone in daily life, mostly serving as seasonings in dishes, so our familiarity with these flavors is relatively limited.

Positive vs. Negative Bitter Flavors

Although the flavors mentioned above may exhibit bitterness, these bitter notes are pleasant, which we refer to as positive flavors. Just as there are positive flavors, there are also negative bitter flavors. Common ones include smoky, woody, medicinal, and burnt notes. These flavors typically produce uncomfortable, throat-irritating, and harsh sensations.

Beyond flavors, many people instinctively use "mellow" to describe the comfortable feeling of a bitter cup of coffee. This mellowness refers to the excellent mouthfeel that dark roasted coffee possesses, making it comfortable to drink. Of course, we can also use terms like rich, full-bodied, and smooth to express this quality.

Brewing the Perfect Bitter Coffee

Whenever customers express a desire for "non-acidic coffee," FrontStreet Coffee's baristas immediately list several "bitter coffees" from their blackboard, including FrontStreet Coffee's Indonesia Golden Mandheling, FrontStreet Coffee's Brazil Queen Estate, and FrontStreet Coffee's Papua PGN Bird of Paradise—three of the most representative varieties. To extract their essence (aromatic notes and rich body), more attention to detail in parameters and techniques is required. Below, FrontStreet Coffee demonstrates with the most popular FrontStreet Coffee Golden Mandheling, teaching everyone step-by-step how to brew a great-tasting cup:

Dark roasting makes the internal structure of coffee beans loose. We can easily crush them with a gentle pinch, indicating strong water absorption when ground into powder. To avoid excessive extraction of bitter substances after the coffee powder absorbs water, FrontStreet Coffee adjusts the grind to be coarser and uses water at a lower temperature for pour-over brewing.

Grind Size and Water Temperature

Grind size is one of the most critical factors affecting coffee taste. When coffee beans are ground into powder and come into contact with hot water, they release large amounts of water-soluble flavor compounds. FrontStreet Coffee uses a specific tool to adjust grind size—a Chinese #20 0.85mm standard sieve. For light to medium roast coffee beans, FrontStreet Coffee typically maintains a 75-80% sieve passage rate, while for medium to dark roast beans, it uses 70-75%. Compared to light roast coffee, the internal structure of medium-dark roasted Mandheling beans is looser, resulting in better water absorption and easier release of large molecular bitter compounds. To avoid over-extraction, FrontStreet Coffee chooses a grind size with a 70% passage rate through the #20 standard sieve.

Water temperature plays a similar role to grind size. The higher the water temperature, the more efficient the coffee extraction, making it easier to release various compounds and resulting in higher concentration. If using near-boiling hot water for brewing, it's easy to extract unpleasant bitter and astringent substances. Therefore, when brewing medium to dark roast coffee beans, FrontStreet Coffee uses different brewing parameters than for light roast beans. Caramelization reactions are more extensive than in light roast beans, making it easier to release bitter large molecular compounds. To avoid extracting excessive impurities, FrontStreet Coffee lowers the water temperature slightly. For light roast coffee, the brewing water temperature is 91-93°C, while for medium to dark roast beans, FrontStreet Coffee recommends 87-88°C.

Brewing Parameters

Recommended brewing water temperature: 87-88°C
Coffee grounds: 15 grams
Coffee-to-water ratio: 1:15
Grind size: Medium-coarse (70% passage rate through Chinese standard #20 sieve)

The brewing method uses a three-stage pouring technique, which can better express the rich body of Golden Mandheling coffee and the sweetness of caramel notes.

The first stage involves a 30ml bloom pour, fully wetting the coffee grounds for degassing, which facilitates better extraction of flavor compounds in subsequent stages. The second stage injects 100ml, primarily to bring out the golden crema of Mandheling and raise the coffee bed.

The final stage involves a gentle 95ml center pour, which enhances the coffee's sweetness, overall presenting a substantial rich body, with caramel sweetness and flavors of chocolate and nuts.

Important Notice :

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FrontStreet Coffee Address: 315,Donghua East Road,GuangZhou

Tel:020 38364473