SCA Coffee Flavor Wheel Analysis Tutorial: How to Properly Describe Pour-Over Coffee Flavor Characteristics and Taste Categories

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Many friends ask FrontStreet Coffee's baristas: "Can you really taste so many flavors in coffee beans? How do you taste them?"

First, this is about personal sensory perception. Everyone encounters different smells and tastes during their growth process. Many flavors in coffee are just close to things we encounter in life, not exactly the same~ When FrontStreet Coffee's baristas experience some general, vague flavors during cupping, they use the coffee flavor wheel to describe flavors and aromas. The coffee flavor wheel can be considered the "flavor dictionary" of specialty coffee, as it contains the flavors presented in specialty coffee—both concrete and abstract—and is an indispensable tool in coffee cupping. As a commonly used tool during cupping, it helps FrontStreet Coffee's baristas find accurate descriptions during cupping. As a professional quality control step that requires professional knowledge, it is crucial for identifying problems in cupped coffee beans and provides significant guidance for adjusting coffee roasting curves and flavor development. Therefore, FrontStreet Coffee believes the coffee flavor wheel is an essential professional auxiliary tool in the cupping process.

What are Coffee Flavors?

When FrontStreet Coffee tastes coffee, it focuses on the performance of four basic tastes: sour, sweet, bitter, and salty, which are closely related to the degree of roasting. Therefore, the Flavor Wheel categorizes by light-to-medium roast and dark-to-heavy roast. Coincidentally, "sour and sweet" taste compounds in light-to-medium roasts have lower molecular weight, higher polarity, and higher water solubility, often dissolving out in the first half of extraction. However, "bitter and salty" taste compounds have higher molecular weight and lower polarity, and lower water solubility, often dissolving out in the second half of extraction.

Coffee beans from light to medium roast are mainly dominated by low to medium molecular weight sour and sweet tastes. However, if there are too many defective beans or improper roasting, even light to medium roasts will produce unpleasant bitter and salty tastes. Dark roasts, on the other hand, are mainly dominated by high molecular weight bitter and salty tastes. But dark roasts are not without merit—the most precious dark roast flavor profile—"rich but not bitter, sweet and smooth on the throat."

The Proportion of Water-Soluble Flavor Compounds in Coffee

The above data shows the weight proportion of soluble taste compounds in roasted coffee beans: sour, sweet, bitter, and salty. Although sweet components are the most abundant, accounting for 39% of soluble compounds, followed by bitter compounds at 26.4%, salty ranks third at 14%, and sour has the lowest proportion at no more than 5.4%, totaling 84.8%. The rest not listed should be taste compounds with lower content. Don't think that just because the sweet proportion is so high, coffee will be as sweet as honey. This is not the case. The bitterness, acidity, or saltiness of black coffee can easily interfere with the original sweetness. The four tastes have complex relationships of mutual cancellation and complementarity.

Follow FrontStreet Coffee to look at a complete coffee flavor wheel.

Are you dazzled? Don't worry, FrontStreet Coffee will break it down one by one and explain in detail what flavors are inside the flavor wheel.

The Four Major Flavor Spectrums in the Coffee Flavor Wheel

FrontStreet Coffee first divides the coffee flavor wheel into four flavor spectrums: sour, sweet, bitter, and salty, to explain the overall flavor direction. Why isn't spicy included? Because spiciness is a pain sensation, not a taste sensation~

1. Sour Flavor Spectrum

Sour taste was originally the biggest characteristic of light to medium roast coffee. Coffee beans contain various organic acids, with phenolic acids, aliphatic acids, and amino acids having the greatest impact on coffee taste. Additionally, during the roasting process, sucrose degradation products gradually degrade from light to medium roast, and concentrations of acetic acid and lactic acid increase accordingly, but at a certain point, they suddenly drop dramatically, so generally, the sour taste of light to medium roast coffee is more obvious.

2. Bitter Flavor Spectrum

The bitter taste of coffee can be classified into two types: pleasant and unpleasant. The former refers to the natural slight bitterness of caffeine, trigonelline, aliphatic acids, and quinine acetate; the latter, unpleasant bitterness, refers to the heavy bitterness of chlorogenic acid degradation products (chlorogenic acid lactones), defective beans, and carbonized particles.

3. Sweet Flavor Spectrum

Although the volatile aroma of caramel can easily be enjoyed through retro-nasal olfaction using the exhalation technique, it's not easy to taste the sweetness of black coffee, because sweetness is often interfered with by other sour, bitter, and salty components, making it difficult to stand out. Unless the sweet components of roasted beans are higher than average, they might break through and be tasted as sweet. In other words, olfaction is much easier than taste for enjoying coffee's sweetness.

The "sweet flavor spectrum" of light to medium roast is the interactive taste of sweetness and acidity, most commonly appearing in high-altitude (above 1300 meters) washed beans. If citric acid, malic acid, and acetic acid content is not low, there will be a sharp acidity, but if the coffee's sugar content is high, it can neutralize some fruit acids, making the sharp acidity become smooth, lively, and dynamic, with fruit flavors and interesting "sweet-sour vibration" tastes.

4. Salty Flavor Spectrum

Although the salty taste of coffee is ubiquitous, it's often masked by the interaction of sour and sweet. Once you taste saltiness in black coffee, it indicates that the organic compounds of sour and sweet have been completely oxidized, causing the inorganic saltiness to be prominent, which can be seen as a warning sign that the coffee has gone off or is not fresh.

Next, FrontStreet Coffee will break down the flavor wheel to see what flavor descriptions there are and which coffee beans represent these flavors.

Floral and Fruity Aromas

Floral (Floral):

Light, slightly sweet, elegant aromatics. Through cupping, FrontStreet Coffee finds the most common floral aromas are jasmine and rose.

Rose— Subtle fragrance type, with a peaceful and soothing feeling. Other representative floral aromas include lavender. The rose aroma of FrontStreet Coffee's Panama Natural Red Label Geisha on the bean menu is most prominent.

Brewing flavors: Bright rose and citrus aromas, brown rice, berries, apricots, complex fruits, honey, with thick juice sensation, rich flavor layers, and obvious sweetness.

Jasmine— Fresh fragrance type, uplifting and energetic aroma. Other representative floral aromas include coffee flowers. There are many coffees with this floral type, such as FrontStreet Coffee's Yirgacheffe Gedeb.

Brewing flavors: Entry has citrus, black tea, with cream and caramel as temperature changes, obvious almond aftertaste and clean, sweet taste.

Fruity (Fruity):

A mixture of slight sweetness and fruit-floral aromas between various mature fruits. Through cupping, FrontStreet Coffee finds the most common fruit aromas are citrus and berry aromas.

Citrus— Clean taste, fresh aroma. FrontStreet Coffee's Ethiopia Yirgacheffe Kochere Washed is most representative.

Brewing flavors: Lemon, floral, orange, sucrose, overall clean and refreshing, honey flavor and oolong tea aftertaste.

Berry— Rich taste with smooth juice sensation. FrontStreet Coffee's Ethiopia Natural Sidamo is most representative.

Brewing flavors: Creamy strawberry aroma at high temperature, passion fruit's sweet and sour as it cools, blackcurrant juice sensation, honey aftertaste, persistent sweetness.

Green/Herbaceous

Under-Ripe: Fruits not yet ripe on the tree, taste similar to grapefruit peel.

Fresh: Freshly cut grass smell.

Dark Green: Cooked green vegetables, like canned spinach that Popeye eats to transform.

Vegetative: Slightly spicy taste of green vegetables, reference given is canned asparagus.

Peapod: Taste of peas and bean products. (Aromatic acids in the sour category, although also beans, focus more on sourness.)

Herb-like: Spice leaves are more appropriate. Such as bay leaves, basil, thyme. FrontStreet Coffee's Colombia Sakura Coffee Beans are most representative.

Brewing flavors: Berry juice-like texture, strawberry jam, mint tea sensation, mugwort, basil aftertaste.

Nuts/Cocoa

Produced during medium roast due to the Maillard reaction. This aroma is quite common, including:

Nut category: Roasted Almonds, Roasted Peanuts, Roasted Hazelnuts, Walnuts.

Cocoa category: Black Chocolate.

These two flavors are most represented by FrontStreet Coffee's Brazil Queen Estate Coffee Beans!

Brewing flavors: Fresh sweetness of sugarcane juice, black tea, soft and smooth fruity sweetness, obvious nutty flavors, balanced and gentle acidity, weak and clean bitterness, rich chocolate aroma and nutty flavors, bright and refreshing taste, smooth and delicate texture.

Sweetness

Caramel aroma produced by sugar browning reaction during medium roast.

1. Toffee, caramel, honey, maple syrup. FrontStreet Coffee's Yirgacheffe Natural Red Cherry is most representative.

The distinguishing feature of the first major category is its "viscosity," which relates to both our mouthfeel and the degree of sweetness, and can also be confirmed through olfaction. We can simply summarize it as toffee > caramel > honey > maple syrup. This viscosity can manifest as: after drinking coffee, smell the bottom of the cup—does it feel greasy or relatively light? Additionally, honey flavor has a bit of sourness and fermentation, while maple syrup smells relatively light with a woody scent.

Brewing flavors: Lemon, licorice, citrus, berries, sweet orange, overall high sweetness, caramel and cream flavors in aftertaste, with black tea aroma.

2. Brown sugar, yellow sugar, white sugar

The second major category distinguishes sucrose by different purity and sweetness. Although in terms of purity white sugar > yellow sugar > brown sugar, in coffee we need to add olfaction, which makes the sweetness in coffee: brown sugar > yellow sugar > white sugar. Different concentrations of sweetness give us different feelings.

Spices

Generally produced during dark roast, including:

Pungent: Sharp nose-like taste, reference given is orange essential oil, with Chinese herbal medicine aroma in taste. Representative coffee is FrontStreet Coffee's Golden Mandheling Coffee Beans.

Brewing flavors: Varied layers, thick and clean, high balance, rich herbal and spice aromas, with chocolate notes, persistent aftertaste, obvious sweetness.

Sour/Fermented

Sour Aromatics: Sour products, such as Bush's Pinto Beans (a type of canned black and white speckled beans).

Citric Acid and Malic Acid: More focused on sourness, astringency, more intense.

Butyric Acid: Taste of certain aged cheeses, such as Parmesan.

Isovaleric Acid: Also taste of certain aged cheeses, such as Romano.

Alcoholic/Fermented

Overripe: Although the reference is banana, it actually refers to the sweet, slightly sour, moist, moldy or earthy taste of other overripe fruits or vegetables.

Winey: Reference is Yellow Tail Cabernet Sauvignon.

Fermented: Reference is Guinness Extra Stout beer.

Whiskey: Reference is Jack Daniel's Tennessee Whiskey Old No. 7. FrontStreet Coffee's Honduras Sherry is representative.

Brewing flavors: Smells of vanilla and cream, with whiskey, berries, almonds, dark chocolate flavors in entry, and maple syrup aftertaste.

Roasted

Acrid: Specifically refers to the bitterness after burning, the bitterness we usually drink is caffeine bitterness, not necessarily the bitterness after burning.

Smoky: Taste of wood ash after burning wood.

Brown, Roast: Purely refers to the feeling of being roasted.

Others (Defect Flavors)

Stale: Lacking freshness, taste of fermented bread, expired bread.

Moldy/Damp: Damp basement smell.

Musty/Dusty: Wheat germ, similar to cereal crumb taste.

Phenolic: This is not a wrong picture, nor a still from Fifty Shades of Grey. This is an old-fashioned tack room, a damp space with animal smells.

Among these, woody aroma is produced by the dry distillation process during dark roast. This flavor receives mixed reviews—those who love it enjoy the woody notes in coffee, while those who don't feel it affects the coffee's original flavors.

How Can Everyone Practice Distinguishing Aromas?

First, this is the entire process of identifying aromas: brain receives information - compares - analyzes - remembers.

We can smell an aroma, taste a flavor, but perhaps we cannot describe it very accurately. The flavor wheel can categorize all human-perceived taste systems concretely, corresponding to the aroma wheel for olfactory systems. By practicing with both together, we can clearly perceive the most subtle differences among all aromas.

For example, when we first eat strawberries, through vision we observe the red appearance and shape of strawberries, through taste we experience the sweet and sour delicious taste of strawberries, combined with olfaction to感受 the aroma of strawberries, as well as the juicy texture of the pulp in the mouth. Most importantly, our brain receives this information, and thus we remember strawberries as a fruit. This is a typical example of how we remember food flavors.

FrontStreet Coffee believes that sensory ability in coffee is an ability to identify and describe. Coffee flavors are so diverse—different regions, varieties, and processing methods can also produce different tastes in coffee. Building a flavor memory bank is about extracting impressions of flavors from our memory, just as we can describe the strawberry flavor in strawberry yogurt because we have eaten strawberries and have strawberry flavor memories in our brain.

Baristas can improve their sensory abilities through calibration with aroma bottles.

However, aroma bottles on the market are currently quite expensive, and after all, aroma bottles are artificially processed, and their flavors may differ from actual aromas. Is there a cost-effective way to improve? That is to source from life—with purposeful intention when eating something. Even for friends who have aroma bottles, FrontStreet Coffee recommends constantly experiencing aromas, flavors, and sensations from life. When we eat fruits, we strive to remember the aroma and taste of these fruits to build our own flavor memory bank. After all, aroma bottles only have 36 flavors, but the describable tastes in coffee are far more numerous. Baristas need to taste extensively, remember, distinguish, and summarize, and as this cycle repeats, sensory abilities can improve bit by bit.

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