tags: [] - coffee/green-beans - coffee/green-beans/grading - coffee/quality aliases: - Coffee grading methods - Physical grading coffee - Sensory grading coffee

Green Coffee Grading Methods¶

Tags: #coffee/green-beans #coffee/green-beans/grading #coffee/quality Aliases: Coffee grading methods, Physical grading coffee, Sensory grading coffee Related: Green Coffee Grading | Green Coffee Defects | Quality Control MOC | Sensory Science MOC Status: ✅ Complete

Overview¶

Green coffee grading uses a combination of physical assessment and sensory (cup quality) evaluation to classify green coffee lots. Physical grading measures what can be seen and measured in the green bean — screen size, density, colour, and defect count; sensory grading determines whether the coffee tastes as good as it looks. Both methods are required together; a lot that passes physical inspection can still fail on cup quality. The full grading framework is covered in Green Coffee Grading.

Physical Grading¶

Screen Size¶

Beans are separated by size using standardised screens with fixed hole diameters, measured in 64ths of an inch. Screen 18 = 18/64 inch = 7.14 mm. Beans are passed through stacked screens; each screen retains beans larger than its holes.

Common size designations:

Screen	Size	Designation
20+	Very large	Supremo
18–19	Large	AA, AAA
16–17	Medium-large	AB
14–15	Medium	B, BB
12–13	Small	C
Below 12	—	Peaberries, triage

Size uniformity ensures even roasting. Larger beans often (not always) indicate higher altitude and greater density, but size does not equal quality — many excellent coffees are small-screened, and the Gesha variety is naturally small.

Density¶

Density reflects altitude and maturation rate. Slow-maturing high-altitude beans develop more complex sugars and harder cell structure. Separation methods include gravity tables (denser beans travel further across a vibrating surface), water flotation (dense beans sink), and pneumatic separation (air currents sort by weight).

Altitude classifications used in density grading:

Classification	Elevation
Strictly Hard Bean (SHB)	1,200–1,650 m+
Hard Bean (HB)	1,000–1,200 m
Semi-Hard Bean	600–1,000 m
Soft Bean	Below 600 m

Colour¶

Visual assessment of bean colour uniformity indicates processing quality and freshness:

Blue-green — Fresh, well-processed washed coffee
Pale/whitish — Old crop, poor storage, or immature beans
Brown/yellowish — Aged, natural process, or storage issues
Dark spots — Fermentation or mould
Uniform colour — Consistent processing and ripeness

Defect-Based Grading¶

Defects are counted in a standardised 350 g sample, weighted by severity (Category 1 vs Category 2 — see Green Coffee Defects), and totalled as full defect equivalents. A lower total corresponds to a higher grade.

Sensory (Cup Quality) Grading¶

Physical grading is only half the assessment. Sensory evaluation using the SCA cupping protocol determines whether the coffee tastes as good as it looks.

Quality score bands:

Score	Classification
90–100	Outstanding
85–89.99	Excellent
80–84.99	Very Good — Specialty grade threshold
75–79.99	Good
70–74.99	Fair
Below 70	Below standard

Even physically defect-free beans can fail on cup: over-fermentation, mould, phenolic contamination, or earthy taint are invisible in green coffee but show clearly in the cup. Sensory evaluation is therefore not an optional verification — it is essential. See SCA Cupping Protocol for the full evaluation method.

Key Facts¶

Physical grading assesses screen size, density, colour, and defect count; sensory grading evaluates cup quality via standardised cupping
Screen size is measured in 64ths of an inch; Screen 18 = 7.14 mm; larger beans tend (not always) to indicate higher altitude
The Strictly Hard Bean (SHB) classification applies to coffees grown above 1,200–1,650 m altitude
The SCA specialty grade threshold is 80 points on a 100-point cup quality scale
Physical and sensory grades together determine final lot classification

References¶

Changelog¶

Date	Change
2026-05-03	Compliance review: added frontmatter, metadata block, all required sections; fixed table alignment; fixed path-prefixed wikilinks; replaced non-coffee tags

This article is part of All-About-Coffee.com - The comprehensive coffee knowledgebase.