The SCA defines a Green Arabica Coffee Classification System (GACCS) based on counting defects on a 350 g sample of beans. The beans are manually inspected for defects, each defect being categorized and counted. The number of occurrences of a given type of defect is normalized to a Full Defects point system based on their severity:
| Category 1 | Occurrences |
|---|---|
| Full Black | 1 |
| Full Sour | 1 |
| Dried Cherry | 1 |
| Fungus Damage | 1 |
| Foreign Matter | 1 |
| Severe Insect Damage | 5 |
| Category 2 | Occurrences |
|---|---|
| Partial Black | 3 |
| Partial Sour | 3 |
| Parchment | 5 |
| Floater | 5 |
| Unripe | 5 |
| Withered | 5 |
| Shell | 5 |
| Broken/Chipped | 5 |
| Hull/Husk | 5 |
| Slight Insect Damage | 10 |
Because SCA mostly cares about Specialty Coffee only, even though GACCS scoring is used to define several unofficial categories, SCA’s Green Been Grading protocol is concerned just one: Specialty Grade. The rest is just not Specialty Grade.
Specialty Grade Green Coffee:
The COB classification is pretty similar to the GACCS in that it translates different severities of defects into a Full Defects scoring system. It’s more punitive for most defects: no such thing as half blacks and half sours; insect damage also scores according to severity but more harshly; hulls, floaters and foreign matter are much more penalized. On the other hand, beans with parchment or fungus damage aren’t evaluated. Here’s the full scoring table:
| Defect | Occurrences | Full Defects |
|---|---|---|
| Black | 1 | 1 |
| Sour or Stinker | 2 | 1 |
| Insect Damage | 2 to 5 | 1 |
| Shell | 3 | 1 |
| Unripe | 5 | 1 |
| Broken | 5 | 1 |
| Withered | 5 | 1 |
| Dried Cherry | 1 | 1 |
| Big Hull | 1 | 1 |
| Small Hull | 2 to 3 | 1 |
| Floater | 2 | 1 |
| Large Foreign Matter | 1 | 5 |
| Medium Foreign Matter | 1 | 2 |
| Small Foreign Matter | 1 | 1 |
As for grading the final tally of the sample, the Brazilian system doesn’t specify named categories. It uses binning to separate ranges into “quality types”.
| Type | Defects |
|---|---|
| 2 | 4 |
| 3 | 12 |
| 4 | 26 |
| 5 | 46 |
| 6 | 86 |
| 7 | 160 |
| 8 | 360 |
Curiously, the grading starts at 2. No official sources explain this but according to some industry professionals, it’s because type 1 would be perfect coffee and there’s no such thing in the real world, which is amusingly corny and aspirational to formalize in commercial classification system.
In practice, this grading system isn’t used very much, even by Brazilian producers. Most buyers of high grade beans will perform their own bean sample analysis instead of just looking the producer’s numbers, while most buyers of low grade beans will buy whatever. In fact, it’s estimated that about 80% of the beans commercialized in the Brazilian internal market are below grade 8, with defects ranging in the 600 to 800 per sample.