tags: [] - coffee/green-beans - coffee/quality-control aliases: - Green coffee defect grading - SCA defect classification - Coffee defect counting

Defect Grading¶

Tags: #coffee/green-beans #coffee/quality-control Aliases: Green coffee defect grading, SCA defect classification, Coffee defect counting Related: Quality Control MOC | Green Coffee Grading | Common Defects | Specialty Coffee | Cupping Status: ✅ Complete

Overview¶

Defect grading is the systematic physical inspection and classification of green coffee to count quality defects before roasting. The SCA (Specialty Coffee Association) green coffee grading standard evaluates a 350 g sample, classifying defects into two categories by severity and applying defined equivalence factors to arrive at a total full-defect count. A coffee must achieve zero Category 1 defects and no more than five full Category 2 defect equivalents — in addition to cupping at 80 points or above — to qualify as specialty grade.

The Two-Category System¶

The SCA green grading system divides defects into two severity categories:

Category 1 (primary defects): Each instance counts as one full defect. Even a single Category 1 defect disqualifies a lot from specialty grade. Examples: full black bean, full sour bean, dried cherry/pod, large foreign matter (stone, stick), severe insect damage.

Category 2 (secondary defects): Multiple instances are required to constitute one full defect equivalent. Typically five Category 2 instances of a given type equal one full defect (some exceptions apply). Specialty grade allows a maximum of five full Category 2 defect equivalents in the 350 g sample.

Specialty Grade Requirements¶

Criterion	Requirement
Sample size	350 g green coffee
Category 1 defects	Zero allowed
Category 2 defect equivalents	Maximum 5 full defect equivalents
Cup score	80+ points on SCA cupping scale
Both criteria	Must be met simultaneously — defect-free green does not guarantee specialty without the cup score

Common Defects and Classification¶

Defect	Category	Equivalence	Cup impact
Full black bean	1	1 per bean	Phenolic, fermented; severe
Full sour bean	1	1 per bean	Vinegar, acetic; severe
Dried cherry/pod	1	1 per cherry	Mouldy, fermented; severe
Large stone or stick	1	5 per object	Equipment damage risk
Partial black bean	2	5 = 1	Moderate off-flavour
Partial sour bean	2	5 = 1	Ferment note in cup
Parchment	2	2–3 = 1	Papery, haylike
Floater	2	5 = 1	Roasts unevenly; grassy, astringent
Immature/unripe bean	2	5 = 1	Astringent, grassy
Shell bean	2	5 = 1	Hollow, pale roast; dilutes cup
Broken/chipped/cut	2	5 = 1	Uneven extraction
Slight insect damage	2	3–5 = 1	Minor off-flavour
Withered bean	2	5 = 1	Light weight; underdevelopment in roast

Grade Tiers¶

Grade	Category 1	Category 2 defects	Cup score
Specialty	0	0–5 full equivalents	80+
Premium	0	6–8 full equivalents	75–79.99
Exchange	0–3	Up to 23 full equivalents	60–74.99
Below Standard	Exceeds limits	—	Below 60

Regional Grading Variations¶

Different producing countries use grading systems that partially overlap with or diverge from the SCA standard:

Brazil: Heavily emphasises defect counting; grade names (Strictly Soft, Soft, Softish, Hard) reflect cup quality and defect profile in a 300 g sample. Screen size and colour are also classified.

Colombia: Screen size (Supremo / Excelso) is the primary classification; European Preparation (EP) designation indicates hand-sorted, near-defect-free lots. Defect counts are secondary.

Ethiopia: Grade 1 (0–3 defects), Grade 2 (4–12), Grade 3 (13–27), with separate grading tracks for washed and natural lots, in a 300 g sample.

Central America: Altitude-based classifications (Strictly Hard Bean, Hard Bean) are primary; European Preparation (EPW) designates defect-sorted lots; hand-sorting is expected for specialty-positioned coffees.

The Grading Process¶

A standard defect grading session: 1. Spread the 350 g sample on a white or black surface under good light 2. Physically sort and separate defective beans by category 3. Count each defect type separately; calculate full defect equivalents for Category 2 using the appropriate equivalence factor 4. Sum Category 1 count and all Category 2 equivalents for the total defect score 5. Record defect types, counts, category totals, date, and grader identity

Electronic colour sorting machines supplement hand-sorting in large-scale operations by detecting colour and density anomalies at high throughput.

Key Facts¶

SCA defect grading uses a 350 g sample; two categories (primary/Category 1; secondary/Category 2)
Specialty grade requires zero Category 1 defects and ≤5 full Category 2 equivalents, plus ≥80 cup score
Full black, full sour, dried cherry, and large foreign matter are Category 1 — each counts as one full defect; any single occurrence disqualifies specialty grade
Category 2 defects use equivalence factors (typically 5 = 1 full defect); up to five full equivalents are permitted in specialty grade
Defect grading and cup score are both required for specialty assessment; a physically clean lot must still cup at 80+ points

References¶

Changelog¶

Date	Change
2026-05-02	Compliance review: full rewrite — removed bold pseudo-header bullet-point glossary format; rebuilt as encyclopedic article with two-category system explanation, defect table, grade tier table, regional variations, grading process; added frontmatter, metadata block, Key Facts, References, Changelog, copyright

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