Green Bean Grading

SCA’s Green Coffee Grading

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 1Occurrences
Full Black1
Full Sour1
Dried Cherry1
Fungus Damage1
Foreign Matter1
Severe Insect Damage5
Category 2Occurrences
Partial Black3
Partial Sour3
Parchment5
Floater5
Unripe5
Withered5
Shell5
Broken/Chipped5
Hull/Husk5
Slight Insect Damage10

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:

Brazilian Official Classification (COB)

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:

DefectOccurrencesFull Defects
Black11
Sour or Stinker21
Insect Damage2 to 51
Shell31
Unripe51
Broken51
Withered51
Dried Cherry11
Big Hull11
Small Hull2 to 31
Floater21
Large Foreign Matter15
Medium Foreign Matter12
Small Foreign Matter11

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”.

TypeDefects
24
312
426
546
686
7160
8360

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.