7.3 Defects, Uniformity & Passing the Descriptive and Affective Practicals
Key Takeaways
SCA-104 limits sensory defects in practice to potato, moldy, and phenolic, with phenolic covering a wide range of expressions.
A defect counts only when both fields are completed: the defective cup numbers and the defect type.
Non-uniform cups must differ qualitatively, with a distinct characteristic present or absent; intensity differences from brewing errors are not penalized.
Every defective cup is also marked non-uniform, except when a coffee is evenly defective across all cups.
The SCA says the Descriptive practical grades form use and descriptive accuracy, and the Affective practical grades form use and consistency.
The uniformity and defect fields on the Affective Form are small boxes with large consequences: each non-uniform cup costs 2 points and each defective cup costs 4. SCA-104 section 5.4 defines exactly when to mark them.
Sensory defects (SCA-104 5.4.1)
A sensory defect is an olfactory or gustatory property of the coffee that is broadly seen as negative. It is distinct from physical defects, such as black or sour beans counted in green grading. SCA-104 states that, in practical terms, sensory defects are limited to three options:
| Defect type | Typical description |
|---|---|
| Potato | Raw, freshly cut potato or earthy-pea aroma; strongly associated with East African coffees |
| Moldy | Mold, damp cellar, or musty-fungal character |
| Phenolic | A wide range of expressions, such as medicinal, iodine-like, or antiseptic notes |
Rules for marking a defect:
- Be sure it is a defect. Before penalizing an "undesirable flavor," you must be clear that it is a defect and be able to identify it specifically as one of the listed types. Avoid catch-all terms.
- Complete both fields. Mark the cup boxes where the defect appears (for example, cups 1 and 5) and select the defect type. If either field is incomplete, the coffee is not counted as defective.
What is not a sensory defect under SCA-104? Fermented, sour, papery, woody, grassy, or roasty notes may lower your impression of quality and may make a cup non-uniform, but they are not marked as defects. Describe them on the Descriptive Form and reflect them in your affective ratings.
Uniformity (SCA-104 5.4.2)
Uniformity is a small discriminative test inside the affective form, made possible because each of the five cups is ground and brewed independently.
- Count qualitative differences only. A cup is non-uniform when a distinctly different characteristic is present or absent compared with the other cups — whether that difference is better or worse.
- Ignore quantitative differences caused by human brewing errors, such as one cup tasting a little stronger or weaker.
- Mark the actual cup numbers. If cups 1 and 5 differ, mark the first and fifth boxes.
Coherence between the two fields
SCA-104 requires the two fields to agree:
- A non-uniform cup does not have to be defective.
- Every defective cup must also be marked non-uniform, with one exception: a coffee that is evenly defective across all cups.
| Situation | Non-uniform cups (u) | Defective cups (d) | Deduction |
|---|---|---|---|
| Cup 2 has a distinct floral note the others lack | 1 | 0 | 2 |
| Cup 4 tastes clearly of potato | 1 | 1 | 6 |
| Cups 1 and 3 phenolic | 2 | 2 | 12 |
| Cup 5 is slightly weaker (brewing error) | 0 | 0 | 0 |
| All five cups equally moldy | 0 | 5 | 20 |
Descriptive practical: form use and accuracy
The SCA says this exam evaluates your ability to perform the Descriptive Assessment accurately, including form use and descriptive accuracy. Practical implications:
- Complete every intensity scale, record integers, and use arrows rather than erasures.
- Respect the selection limits: up to 5 olfactory descriptors per list, up to 2 main tastes, up to 2 mouthfeel qualities.
- Choose the boxes that best represent the coffee; a broad scatter of checks lowers accuracy.
- Add freely elicited words for acidity and sweetness every time.
Affective practical: form use and consistency
The SCA says this exam evaluates your ability to perform the Affective Assessment accurately, including form use and consistency. Practical implications:
- Rate all eight sections, and use the final box when you changed a rating.
- Apply the uniformity and defect rules above exactly.
- Keep your scale stable: similar coffees should receive similar ratings, and differences in your ratings should reflect differences you can describe.
- Justify ratings with short affective notes.
Preparation the SCA recommends
- Review the Descriptive Assessment and Affective Assessment sections of the CVA Protocol and SCA-103 and SCA-104.
- Download the forms and run assessments at work if you lack professional experience with them.
- Sensory Skills Foundation and Intermediate introduce the forms and build acuity. CVA for Cuppers gives experienced cuppers a thorough introduction to the Descriptive, Affective, and Extrinsic Assessments.
Frequent mistakes
| Mistake | Correct practice |
|---|---|
| Marking "ferment" or "sour" as a defect | Only potato, moldy, or phenolic count as defects; reflect other negatives in ratings |
| Checking a defect type but not the cups | Both fields are required, or the defect does not count |
| Marking a defective cup but not marking it non-uniform | Mark both, unless all cups are evenly defective |
| Calling a weaker cup non-uniform | Intensity differences from brewing are not penalized |
| Copying descriptive notes into affective notes | Affective notes justify the rating instead |
| Letting another cupper's reaction change your rating | SCA-104 says ratings must not be influenced by others |
A consistency drill for practice
- Ask a colleague to set a table of five coffees, two of which are the same coffee under different codes.
- Complete a Descriptive and an Affective Form for every coffee without discussion.
- Unblind the table and compare your two records for the repeated coffee: intensity ratings, CATA boxes, affective ratings, and score.
- Note any section where your two ratings differ by more than one point, and taste that coffee again to understand why.
Repeating this drill each week shows whether your scale is stable, which is the kind of consistency the Affective practical rewards.
Which sensory defects does SCA-104 recognize on the Affective Form?
Fermented, sour, and earthy
Potato, moldy, and phenolic
Taint and fault
Quaker, baked, and scorched
A cupper selects "phenolic" as the defect type but forgets to mark which cups were affected. How does SCA-104 treat the coffee?
It is counted as defective in all five cups
It is counted as defective in one cup by default
It is not counted as defective; both fields are required
It receives a 2-point uniformity deduction instead of the 4-point defect deduction
One cup of five tastes slightly stronger than the others because of a minor pouring error, with no different characteristics. How should uniformity be marked?
Mark the cup as non-uniform and deduct 2 points from the cupping score
Mark the cup as defective and deduct 4 points
Mark all five cups as non-uniform
Leave it uniform; only qualitative differences count
Sections you finish are checked off in the contents.