Nav: Home > Coffee >

Grading of Kenya Premium Coffee Beans: What Do AA, AB, and PB Mean in Kenyan Coffee

Published: 2026-01-27 Author: FrontStreet Coffee

Last Updated: 2026/01/27, Coffee is graded when it is still green coffee beans before roasting. Any single coffee tree can produce all grades of coffee, from E to C, which are then sorted by size. This is done for roasting consistency, as similarly sized beans roast at similar rates, while beans of different sizes roast unevenly (for example, smaller beans may burn while larger beans remain under-roasted).

Kenya coffee beans have adopted a strict grading system since the 1930s, primarily based on the size, shape, and hardness of the beans. The grading hierarchy from highest to lowest includes AA or AA+, AB, PB, C, E, TT, and T. This classification serves as a selection reference, while coffee flavor is also taken into consideration. Currently, the most common grades available in the mainstream market are AA, AB, and PB.

Coffee Size Grading

AA grade is a classification name for green coffee beans, primarily referring to bean size. AA grade indicates larger coffee beans, generally those with a particle size of 17 mesh or above (17 mesh = sieve aperture diameter of 6.75mm). AA size corresponds to 17 and 18 mesh, while AB is 15 and 16 mesh.

AA Plus (AA+): Exceptionally high cup quality (flavor, mouthfeel) among AA grade beans
AA particle size (Screen Size): 17-18
AB particle size (Screen Size): 15-16, accounting for the majority of production
C particle size (Screen Size): Smaller than AB
TT: Lighter beans separated from AA and AB grade beans using air screeners
T: Lighter beans separated from C grade beans using air screeners
E Elephant Bean: Large mutant beans where two beans have merged, also known as Elephant ear beans
UG: Those that do not meet the above standards
PB Peaberry: Classified by shape, unrelated to flavor or weight

Flavor Grades

In addition to size grades, Kenya also employs a flavor grading system using TOP, PLUS, and FAQ classifications to select delicious coffees. The evaluation criteria include: green beans (size, color, defects), roasted beans, and cupping quality (acidity, body, flavor characteristics, defects). In practical application, they simplify this to scoring each bean on Acidity-Body-Flavor, with each category rated 1-3 points. If a bean is marked 1-1-1, it corresponds to TOP AA grade.

The Kenya Assalia coffee beans, launched by FrontStreet Coffee's own roasting, belong to the AA grade. They come from the Thika region and have undergone the Kenyan 72-hour wet processing method. The varieties are SL28 and SL34, making it a top choice for many acidity coffee lovers. If you're tasting this Kenya Assalia coffee bean for the first time, FrontStreet Coffee suggests trying hot pour-over black coffee to better experience the flavor characteristics of Kenyan coffee.

Brewing Suggestions

Considering that these beans are lightly roasted, FrontStreet Coffee recommends using higher water temperature and a faster flow rate dripper. This is mainly to extract the bright acidity with high temperature, but to avoid over-extraction due to high temperatures, the faster flow V60 dripper is chosen. The main parameters used are: V60 dripper, coffee-to-water ratio 1:15, 15g coffee grounds, water temperature 91°C, and grind size (80% pass-through rate with #20 standard sieve).

In terms of brewing technique, FrontStreet Coffee adopts a segmented extraction method, also known as the three-stage pouring method. Pour 30g of water for a 30-second bloom, followed by 125g in the second circular pour. When the water level drops to just before exposing the coffee bed, continue pouring to 225g. The total brewing time is 2 minutes (including the bloom).

The flavor of Kenya Assalia coffee: The initial sip reveals flavors of dark plum and cherry tomatoes, with intense and substantial acidity. The mid-palate offers prominent sweetness with a juicy sensation, while the afternotes carry berry fruit aroma and brown sugar sweetness, accompanied by green tea fragrance.