14.2 World Coffee Research Sensory Lexicon & Reference Standards
Key Takeaways
The WCR Sensory Lexicon identifies 110 flavor, aroma, and texture attributes and was created at the Sensory Analysis Center at Kansas State University.
Each lexicon attribute has a definition, one or more references, an intensity score on a 15-point scale, and preparation instructions.
Lexicon 2.0, published in October 2017, added globally available FlavorActiV references for 24 attributes, including sour, bitter, and salty.
In the 2016 lexicon, a 2-inch square of cardboard in half a cup of water anchors cardboard aroma at 7.5.
SCA-103 cites WCR Lexicon references for its mouthfeel terms: alum solution for mouth-drying and potassium chloride solution for metallic.
The World Coffee Research (WCR) Sensory Lexicon is the dictionary behind the modern Coffee Taster's Flavor Wheel. It turns words like "blackberry" or "papery" into something you can smell or taste, at a known intensity. Q Grader candidates use it in two ways: as the source of main-taste practice solutions (Section 2.2), and as the reference for the flavor categories on the CVA Descriptive Form.
Origin and scope
- WCR describes the lexicon as "the largest collaborative research project on coffee's flavors and aromas ever done." It was created at the Sensory Analysis Center at Kansas State University.
- It identifies 110 flavor, aroma, and texture attributes present in coffee and provides references for measuring their intensity.
- The first edition appeared in 2016. Lexicon 2.0 (October 2017) added globally available, shelf-stable FlavorActiV references for 24 attributes — sour, bitter, salty, apple, grape, coconut, pineapple, acetic acid, butyric acid, isovaleric acid, fermented, peapod, fresh, papery, musty/earthy, musty/dusty, moldy/damp, phenolic, petroleum, brown spice, almond, vanillin, floral, and jasmine.
- Many first-edition references were grocery products mainly available in the United States, which is why the globally available references were added.
- The lexicon is free to download for personal use.
How an entry is built
Each attribute has five parts:
- Name — for example, Blackberry.
- Definition — "the sweet, dark, fruity, floral, slightly sour, somewhat woody aromatic associated with blackberries."
- Reference(s) — a product or chemical that shows the attribute.
- Intensity score — the strength of that reference on the lexicon's 15-point scale.
- Preparation — how to serve it. Aroma references usually go in covered glass snifters so that aromas do not contaminate each other.
Some attributes have several references. The lexicon's example is Smoky, with three aroma references and one flavor reference. The same reference can also serve two attributes; roasted peanuts are used for both Peanut and Roasted.
Using intensity scores
The intensity scores make the lexicon a measuring tool, not only a vocabulary. The lexicon explains this with hazelnut: 1/8 teaspoon of imitation hazelnut extract in a cup of milk scores 3.5, and double strength scores 6.0. A coffee whose hazelnut note is clearly above the first reference and a little below the second might be scored 5.5.
Verified reference examples (2016 edition)
| Attribute | Reference | Intensity | Preparation (summary) |
|---|---|---|---|
| Sweet (taste) | 1.0% sucrose solution | Flavor 1.0 | 1-ounce covered cup |
| Sour (taste) | 0.015% and 0.05% citric acid | Flavor 1.5 and 3.5 | 1-ounce covered cup |
| Bitter (taste) | 0.01%, 0.02%, 0.035%, 0.05% caffeine | Flavor 2.0, 3.5, 5.0, 6.5 | 1-ounce covered cup |
| Salty (taste) | 0.15% sodium chloride | Flavor 1.5 | 1-ounce covered cup |
| Blackberry | Smucker's blackberry jam | Flavor 5.5 | Jam in a 1-ounce covered cup |
| Peach | Fresh peach pit; Jell-O peach powder | Aroma 8.0; Flavor 7.0 | Pit in a snifter; dry powder in a cup |
| Grape | Welch's 100% Concord grape juice | Flavor 5.0 | 1 part juice to 1 part water |
| Lemon | Fresh lemon juice | Aroma 5.0; Flavor 7.0 | 1 part juice to 4 parts water |
| Black tea | Lipton black tea | Aroma 8.0; Flavor 7.0 | Leaves wetted in a snifter; 5-minute brew for flavor |
| Peapod | Le Nez du Café no. 3 "garden peas" | Aroma 7.0 | One drop on a cotton ball in a snifter |
| Cardboard | Cardboard | Aroma 7.5 | 2-inch square in half a cup of water |
| Papery | Coffee filters soaked overnight in boiling water | Flavor 2.5 | Soaking water served in a cup |
| Phenolic | Phenylacetic acid | Aroma 6.0 | 0.15 g in a snifter |
Mouthfeel references
| Attribute | Reference | Intensity |
|---|---|---|
| Mouth drying | 0.05% and 0.07% alum solution | 2.5 and 3.5 |
| Thickness | 5% sucrose solution; tomato juice | 2.0; 4.0 |
| Metallic | 0.10% potassium chloride solution | 1.5 |
| Oily | 1% low-fat milk; half-and-half | 3.0; 6.0 |
SCA-103 points to the WCR Lexicon for two of its mouthfeel examples: alum solution for mouth-drying and potassium chloride solution for metallic.
How the lexicon relates to the CVA
| Feature | WCR Lexicon | CVA Descriptive Form |
|---|---|---|
| What is rated | Intensity of each specific attribute (for example, blackberry) | Total intensity of each cupping section (for example, flavor) |
| Scale | 15-point intensity scale | 15-point intensity scale |
| Vocabulary | 110 attributes | CATA categories based on the Flavor Wheel, plus free descriptors |
| Typical user | Trained descriptive panels in research | Professional cuppers, buyers, and QC labs |
The two tools share a philosophy — intensity is not quality — but they measure at different levels of detail. A research panel might score blackberry at 4.0 and cocoa at 3.0; a CVA cupper rates total flavor intensity and checks Berry, Fruity, and Cocoa.
Training with the lexicon
- Taste basics first. Prepare the sweet, sour, salty, and bitter references and learn their intensity steps, as the SCA recommends for the Main Taste Solutions practical.
- One family per session. For example, prepare lemon, grapefruit, and orange references for Citrus Fruit.
- Bracket a coffee. Place a coffee between two references of the same attribute and estimate its score, as in the hazelnut example.
- Respect preparation notes. The intensity of a reference holds only when it is prepared as written.
How many attributes does the World Coffee Research Sensory Lexicon identify?
36
86
110
250
In the WCR Lexicon's example, hazelnut references score 3.5 and 6.0. A coffee's hazelnut note is clearly stronger than the first and slightly weaker than the second. What score fits?
About 2.0
About 5.5
Exactly 6.0
About 9.0
Which WCR Lexicon reference does SCA-103 cite as an example of the metallic mouthfeel?
Alum solution (0.05%)
Tomato juice
Half-and-half dairy cream
Potassium chloride solution
Sections you finish are checked off in the contents.