8.3 Category 2 (Secondary) Defects & Allowable Limits

Core Knowledge: Category 2 (Secondary) defects encompass physical imperfections, mechanical injuries, physiological anomalies, and minor harvesting flaws that degrade green coffee uniformity and cup cleanliness. Unlike primary defects, a limited number of secondary defects is commercially tolerable: the heritage specialty grade allowed no more than 5 full defects in a 350-gram sample.

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The Secondary Defect Framework & Grade Classifications

While primary defects are biologically destructive and carry zero tolerance, secondary defects represent common harvest and post-harvest challenges. A lot containing small mechanical chips from aggressive dry milling or a few withered beans from dry-spell stress can still cup cleanly and express complex varietal character, provided the aggregate defect load remains tightly controlled.

The heritage SCA classification, which the CVA Physical Assessment builds on, defined two grades:

1. Specialty Grade: 0 Category 1 defects and no more than 5 full defects in 350 g; no quakers in a 100 g roasted sample; moisture 9–13%; at least one distinctive cup attribute.
2. Premium Grade: no more than 8 full defects in 350 g, with Category 1 defects permitted; no more than 3 quakers in 100 g roasted.

Coffee outside these limits was below specialty grade. The CVA Physical Form records the counts without printing a grade, so in the practical your task is accurate counting and conversion.

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The Ten Category 2 (Secondary) Defects

Graders must memorize the ten secondary defects, their conversion factors, morphological characteristics, and sensory manifestations:

1. Partial Black (Negro Parcial)

• Morphology & Cause: Less than 50% of the bean surface is blackened, discolored, or necrotic. Caused by localized bacterial infections, light frost damage, or interrupted drying where localized moisture pockets ferment.
• Cup Impact: Harshness, slight sourness, ashy or dirty notes, and reduced sweetness.
• Defect Ratio: 3 beans = 1 full defect (3:1).

2. Partial Sour (Vinagre Parcial)

• Morphology & Cause: Less than 50% of the bean surface exhibits a reddish-yellow or pale amber waxy discoloration; internal cross-section remains pale without deep yellow decay. Caused by minor fermentation delays, slightly polluted wash water, or damp storage.
• Cup Impact: Tart, cidery, sour fruit, or faint fermented notes.
• Defect Ratio: 3 beans = 1 full defect (3:1).

3. Parchment (Pergamino)

• Morphology & Cause: A bean fully or partially encapsulated in its tough, fibrous, straw-colored endocarp (parchment shell). Caused by improperly adjusted dry mill hullers (excessive roller clearance), worn huller knives, or damaged screens allowing unhulled parchment to bypass.
• Cup Impact: Woody, papery, and dry straw notes. In the roaster drum, loose parchment shells ignite easily at high temperatures, creating localized smoke taints and presenting a serious flue fire hazard.
• Defect Ratio: 5 beans = 1 full defect (5:1).

4. Floater (Flotador)

• Morphology & Cause: Distinctly pale, bleached white, light cream, or yellow bean with an abnormally light specific gravity and spongy texture. Caused by incomplete development on the tree, prolonged drought, improper storage under humid conditions, or failure of flotation siphons at the wet mill.
• Cup Impact: Flat, woody, cardboard, hay, and an empty, hollow cup lacking sweetness and acidity.
• Defect Ratio: 5 beans = 1 full defect (5:1).

5. Immature / Unripe (Inmaduro)

• Morphology & Cause: Smaller than average bean with sharp edges, a concave ventral face ("boat-shaped"), and a tightly adhering, pale green or silver-metallic silverskin (integument) that cannot be rubbed off. Caused by harvesting unripe, green cherries.
• Cup Impact: Astringent, grassy, vegetative, bitter, and straw-like flavors.
• The Roasted Quaker Connection: Immature beans contain immature starch structures and virtually zero sucrose. Because sucrose is the primary chemical precursor for caramelization and Maillard browning, immature beans fail to roast properly. They remain pale yellow or light tan in the roast—transforming into quakers that ruin cup sweetness and impart peanutty, cardboard taints.
• Defect Ratio: 5 beans = 1 full defect (5:1).

6. Withered (Arrugado)

• Morphology & Cause: Small, lightweight bean with a deeply wrinkled, prune-like surface and distorted shape. Caused by severe drought during cherry filling, or premature defoliation of coffee trees by Coffee Leaf Rust (Hemileia vastatrix).
• Cup Impact: Thin body, astringent finish, grassy and straw-like taints.
• Defect Ratio: 5 beans = 1 full defect (5:1).

7. Shell / Elephant Ear (Concha)

• Morphology & Cause: Malformed bean resulting from false polyembryony (a genetic/physiological condition where multiple embryos develop within a single locule). During hulling, the bean splits into an outer concave, cup-shaped shell ("ear") and a dense, cylindrical or conical inner core.
• Cup Impact: The thin, paper-like outer shell roasts much faster than normal beans, scorching and burning to ash, while the dense inner core remains underdeveloped—imparting simultaneous burnt/charred and grassy/raw taints.
• Defect Ratio: 5 beans = 1 full defect (5:1).

8. Broken / Chipped / Cut (Quebrado / Cortado)

• Morphology & Cause: Beans mechanically sliced, cracked, or fractured. If less than half the bean is severed, it is termed chipped; if broken in half or into smaller fragments, it is termed broken. Caused by improperly spaced pulper knives, over-tightened huller friction screws, or rough handling in mechanical screw conveyors.
• Cup Impact: Irregular surface area causes rapid scorching at fractured edges, producing woody, burnt, and earthy taints.
• Defect Ratio: 5 beans = 1 full defect (5:1).

9. Hull / Husk Fragment (Cáscara / Pipa)

• Morphology & Cause: Dried fragment of outer cherry skin and dried pulp (exocarp/mesocarp), dark brown to black in color. Caused by inadequate pneumatic air aspiration in dry mills or damaged vibrating sorting screens.
• Cup Impact: Dirty, earthy, burnt, smoky, and astringent notes.
• Defect Ratio: 5 fragments = 1 full defect (5:1).

10. Slight Insect Damage (Broca Ligera)

• Morphology & Cause: A bean exhibiting exactly 1 or 2 small puncture holes caused by the Coffee Berry Borer (Hypothenemus hampei), without structural collapse or extensive internal tunneling.
• Cup Impact: Mild loss of cup clarity, faint woody or dirty taints.
• Defect Ratio: 10 beans = 1 full defect (10:1).

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Category 2 Defect Conversion Table

Memory Key: Remember the exceptions: Partial Black and Partial Sour are 3:1, Slight Insect Damage is 10:1, and every other Category 2 defect is 5:1.

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Defect Tallying & The Precedence Rule

Calculating full defect equivalents requires precise arithmetic. On the CVA Physical Form, the evaluator records the raw count for each defect, divides by the conversion ratio, and enters the resulting full defect equivalent.

The Severity Precedence Rule

A useful counting convention is the precedence rule (hierarchy of severity): When an individual bean displays characteristics of more than one defect (for example, a bean that is both chipped and has two insect holes, or an immature bean that is partially black), it must be categorized under the single defect of highest severity.

  HIGHEST SEVERITY (Category 1)                               LOWEST SEVERITY (Category 2)
  ┌───────────────────────────────────────────────────────────────────────────────────────┐
  │ Full Black / Full Sour / Fungus > Partial Black / Partial Sour > 5:1 Secondary Defects│
  └───────────────────────────────────────────────────────────────────────────────────────┘

• Never Double-Count: A single bean must never be counted in two defect categories. Counting a bean twice invalidates the grading sheet.
• Example: A bean with a broken edge and 3 insect holes must be classified under Severe Insect Damage (Category 1), not Broken (Category 2).

Worked Grading Calculation Example

Suppose a 350-gram sample yields the following raw defect counts:

• Category 1 Defects:
  • Full Black: 0 beans
  • Full Sour: 0 beans
  • Dried Cherry Pod: 0 pods
  • Fungus Damage: 0 beans
  • Foreign Matter: 0 items
  • Severe Insect Damage: 0 beans
  • Category 1 Full Defects = 0.00 (Passes Zero-Tolerance)
• Category 2 Defects:
  • Partial Black: 3 beans $\div 3 = 1.00$ full defect
  • Partial Sour: 3 beans $\div 3 = 1.00$ full defect
  • Parchment: 5 beans $\div 5 = 1.00$ full defect
  • Immature: 5 beans $\div 5 = 1.00$ full defect
  • Broken / Chipped: 5 beans $\div 5 = 1.00$ full defect
  • Slight Insect: 3 beans $\div 10 = 0.30$ full defect
  • Total Category 2 Full Defects = 1.00 + 1.00 + 1.00 + 1.00 + 1.00 + 0.30 = 5.30 full defects

Grade Determination: Because the total of 5.30 exceeds the heritage specialty limit of 5 full defects, this sample would fall to premium grade under the heritage classification. On the CVA Physical Form you would simply record the counts and the 5.30 total.