Quality Metric
Defects
Physical or sensory flaws in green coffee. Primary defects cause cup faults. Secondary are less severe. Defect counts determine grade--and directly affect what ends up in your roaster.
Definition
What defects are
Coffee defects are physical abnormalities or processing flaws that affect cup quality. They're counted in a 300-gram green sample and categorized as primary (serious) or secondary (less severe).
Defect counts directly determine coffee grade. Grade 1 Ethiopian coffee allows 0-3 full defects. Grade 2 allows 4-8. Higher defect counts mean lower grades.
Key concepts
Defect Categories
Primary vs. secondary defects
Primary Defects (1 = 1 full defect)
- Full black: Completely blackened bean. Causes harsh, ashy taste.
- Full sour: Fermented beyond acceptable. Vinegar taste.
- Fungus damage: Mold-affected. Musty, moldy flavor.
- Foreign matter: Sticks, stones, debris.
- Dried cherry: Unremoved fruit. Fermented taste.
Secondary Defects (5 = 1 full defect)
- Partial black: Partially blackened. Less severe.
- Partial sour: Slight ferment. May pass in blend.
- Floater: Low density. Underdeveloped.
- Immature/quaker: Underripe cherry. Roasts pale.
- Broken/chipped: Mechanical damage. Uneven roast.
- Insect damage: Bored holes. Usually minor impact.
Why Roasters Care
What defects mean for you
Cup quality
Primary defects cause cup faults--literally off-tastes that ruin the cup. One full black bean can affect multiple cups in a batch.
Roast consistency
Quakers and density variation cause uneven roasts. You'll see pale beans scattered in dark roasts. Visual quality drops.
Grade selection
Higher grades cost more but require less sorting. For single origins, Grade 1 is worth it. For blenders, Grade 4 may suffice.
Our Approach
How we handle defects
Grade what we sell
Every lot is graded using standard SCA defect counting. You'll know the grade before you buy.
YirgZ zero-defect standard
Our YirgZ trademark goes beyond Grade 1. Actually zero primary defects per 300g sample.
Reject problematic lots
We walk away from lots with defect patterns that suggest systemic problems--even if the count technically passes.
Offer Grade 4 for blenders
Not every roaster needs Grade 1. We offer lower grades at appropriate prices for blend components.
Current Inventory
Ethiopian coffees by grade
WUSH WUSH
Oromia, Hambela
Sangaria | Fruit Bomb | Floral | Sweet Finish
Natural, 120 hours dry Fermentation! · In Stock
Natural ARDI
Sidama, Damo
Clean Strawberry | Peach | Sweet Finish
Natural · In Stock
Harrar Gr 1
Oromia, Micheta
Chocolate | Barries | Carmel | Full Body
Natural · In Stock
Washed GUJI
Oromia, Bensa
Black Tea | Floral | Bergamot
Fully washed · In Stock
NATURAL SIDAMA GR 4
Sidama
Dark Chocolate | Nuts | Medium Acidity | Complex | Comforting
Natural · In Stock
SWD Natural Sidama
Oromia, Sama
Hint of fruit, Apple | Sweet
SWD · In Stock
Deep Dive
Green Coffee Defects & Grading Standards
SCA defect categories, how to interpret a grading report, and why zero-defect protocols matter for roast consistency.
Related Terms
More Quality Metrics
Water Activity (aW)
Measure of free moisture. Below 0.60 is stable; above 0.65 risks mold.
Moisture Content
Percentage of water in green coffee. Target 10-12% for stability.
Density
Bean mass per volume. Affects heat transfer and roast development.
Q Score
Cupping score from a certified Q-grader. 80+ is specialty grade.
Q Grader
Licensed coffee professional certified by CQI to evaluate specialty coffee.
Screen Size
Bean size measured by round-hole screens. Larger = more uniform roasts.
Want clean, graded coffee?
Request samples and we'll share grade, defect counts, and cupping notes.