How Green Coffee Bean Grades Differ by Country

Letter codes such as AA and G1 on a coffee bag refer to the green coffee bean grading systems used at origin, not to roast level or flavor. Ethiopia sorts beans by the share of defects in a 300-gram sample, so washed lots usually land at G1 to G2, while natural lots once fell to G3 to G5 before processing improved.

Grading rules change from country to country. Since the Ethiopia Commodity Exchange was set up in 2008, Ethiopian lots are judged on both physical defects and cupping score, split into specialty and commercial types. Kenya instead sorts by bean size, using grades like AA, AB and PB, so the same letters can mean different things across origins.

When buying coffee beans, you often see letter codes like AA and G1 on the packaging. They actually represent the green bean grading systems of different origins. In this article, Front Street Coffee will walk you through Ethiopia's G1 to G5 grades based on the proportion of defective beans, as well as the nine-level classification adopted after the ECX was established, which combines physical characteristics with cupping scores. We will also introduce Kenya's eight grades—AA, AB, PB, and others—distinguished by bean size, and briefly mention the grading criteria of Colombia, Jamaica, Brazil, and other countries, so that you can better understand what these labels really mean when buying beans.

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Specialty coffee is increasingly entering the public eye, and many people have started buying their own coffee beans, grinding them, and brewing pour-over. Have you ever noticed those puzzling letter combinations printed on coffee packaging, like AA or G1? What exactly do these symbols mean?

Today, Front Street Coffee will decode the meaning behind these letters on coffee packaging one by one.

Ethiopia (graded by the proportion of defective beans)

Before the Ethiopia Commodity Exchange (ECX) was established, Ethiopia's coffee export grades were set by the CLU (Cupping and Liquoring Unit) under the Ministry of Agriculture. This department mainly graded green beans based on the number of defective beans in a 300-gram sample. The specific standards are shown in the table below.

Typically, washed beans were mostly classified as G1 to G2, while, limited by the early level of natural processing, natural green beans had more defects and were often classified as G3 to G5. However, with the continuous advancement of natural processing techniques, natural beans can now also reach the G1 to G2 level.

After the ECX (Ethiopia Commodity Exchange) was established in 2008, grading was changed to a system that comprehensively evaluates the physical attributes of green coffee beans and their cup profile characteristics.

Based on the processing method, ECX defines two major categories—unwashed and washed—as three types:

a. Specialty—few defects and high cupping flavor quality

b. Commercial—not reaching specialty level, but superior to the local/domestic consumption grade

c. Local/Domestic—coffee with a large number of defective beans (unripe beans), or poorer flavor due to being out of season or improper storage

Among these, the Specialty and Commercial categories are exported to the international market. ECX divides green beans into nine grades based on the combined score of physical characteristics and cup profile, with physical characteristics accounting for 40% and cupping quality accounting for 60%.

Physical characteristics (40%):

Washed processing: number of defects (20%), appearance size (10%), color (5%), odor (5%)

Unwashed processing: number of defects (30%), odor (10%)

Cupping quality (60%)

G1 to G3 are then cupped again according to SCAA standards to assess their flavor attributes in more detail: G1 and G2 scoring no less than 85 points are rated as Q1; G1, G2, and G3 scoring between 80 and 85 points are rated as Q2; and all G1, G2, and G3 scoring below 80 points are uniformly classified as G3.

Q1 and Q2 are exported as specialty grade, while G4 to G9 maintain their original grading unchanged and are exported as commercial grade together with G3.

Kenya (graded by bean size)

Kenyan coffee grading mainly depends on bean size, and it is generally divided into eight grades.

E (Elephant Bean): Here, "E" is short for Elephant, but it does not refer to the Maragogype variety. Instead, it is a bean that appears as a single bean due to abnormal development in which two seeds become intertwined, and it falls into the category of defects. Generally, a fruit contains two seeds that press against each other face-to-face, so one side is relatively flat; this is called a flat bean or female bean. Grade E beans are formed when two seeds stick together and merge during growth, becoming especially large. Grade E beans are about 18 screen size or larger (one screen equals 1/64 inch), and their production is very rare.

AA: This grade is about 17 to 18 screen size (about 6.7 to 7.1 mm), and it is the most frequently mentioned Kenyan coffee grade. In the specialty coffee world, it is often called AA TOP, and it is also the bean many coffee shop owners feature. However, AA is not necessarily equivalent to the best; it only reflects bean size and should not be confused with flavor.

AB: Most coffee beans fall into this grade. It is called AB because A is 6.80 mm and B is 6.20 mm, and beans of these two sizes (Grade A and Grade B) are often sold mixed together, hence AB. The size is about 15 to 16 screen (about 6.0 to 6.4 mm).

C: The bean size is about 14 to 15 screen (about 5.6 to 6.0 mm), slightly smaller than Grade B.

PB: The full name is Peaberry, also called small round bean, or male bean. Compared with ordinary flat beans, it is likewise uncommon, accounting for about one-tenth of all coffee beans. It forms because only one seed develops fully inside the fruit, resulting in a small, round bean. Some people particularly prefer the flavor of PB, so it is often sorted out and sold separately.

TT: These beans are light beans screened out from AA and AB by an air separator. They are usually relatively light in weight, fail to meet hardness standards, and contain broken and defective beans.

T: Lighter beans screened out from Grade C beans, mixed with broken beans and even fragmented pieces.

MH/ML: This type of coffee bean is not used for export. It usually consists of overripe beans that have fallen to the ground and is of poor quality, accounting for about 7% of all coffee beans. It is supplied only to Kenya's domestic market.

There are also many other countries that grade by green bean size, such as Tanzania, Rwanda, Colombia, Jamaica, and others.

Colombia

Jamaica

Costa Rica, Panama, Guatemala (graded by green bean hardness)

At the same latitude and in the same plot, the higher the altitude, the greater the temperature difference between day and night, the longer the coffee growing period, the harder the beans, the more nutrients they absorb, and the more prominent the flavor compounds.

El Salvador, Honduras (graded by altitude)

Brazil (graded by bean size, defect rate, and cupping score)

Brazil believes that only completely defect-free beans can be called NY.1, and completely defect-free beans do not exist. Therefore, among Brazilian green beans, the best grade is NY.2.

By coffee bean size (NY grading method)

By number of defective beans

By cupping level, they are divided into: Fine Cup (FC), Fine, Good Cup (GC), Fair Cup, Poor Cup, Bad Cup

For example: Brazil Cerrado NY-2 SC-17/18 FC

This means that in Brazil's Cerrado region, the NY grading method grade is 2, the coffee bean size is 17 to 18 screen, and the flavor quality is Fine Cup.

For more specialty coffee beans, please add the private WeChat of Front Street Coffee (FrontStreet Coffee), WeChat ID: kaixinguoguo0925.

The above content is compiled by CoffeeHunters, a coffee news website.