How Does the Kenya Coffee Grading System Work?

Kenya coffee labels carry letter codes such as AA, AB, C, PB, E, TT, T and MH/ML, and these come from the country's official grading system. Unlike Ethiopia, which grades by defect count, and much of Central and South America, which grades by growing altitude, Kenya sorts beans mainly by particle size, then adds shape and hardness into a combined score. AA sits at the top of the list.

Bean size is not the only factor, which is why two bags marked AA can taste different. Traders sometimes apply their own secondary labels on top of the official coffee bean grades, so the printed letters do not guarantee a specific cup profile. Roasters and buyers still cup each lot, and an AA lot from a washed station may be roasted and brewed differently from an AB lot.

Kenyan coffee occupies a pivotal position in the global specialty coffee landscape, and its bright, uplifting acidity and rich layering have captivated countless coffee enthusiasts. But when faced with the letter combinations like AA, AB, and PB on Kenyan coffee bean labels, many people are not clear about what they actually mean. In fact, these designations originate from Kenya's official coffee grading system, which comprehensively takes into account multiple factors such as bean size, shape, and hardness. This article will systematically sort out Kenya's complete coffee grading system, explain the specific standards of each grade, and clarify the difference between the secondary grading set by green bean traders themselves and the official grades. At the same time, Front Street will also combine its own bean-selection experience to share the roasting and brewing approach for an AA-grade Kenyan bean from the Asaliya washing station.

"What exactly do these suffixes represent?" Recently, quite a few customers have raised this question at Front Street's brick-and-mortar store. To put it plainly, they are the same in nature as the G1 and G2 markings on Ethiopian coffee beans—both are symbols used to distinguish coffee bean grades.

Front Street once discussed in the article "The Three Major Coffee Bean Grading Systems" that, in order to allow growers, buyers and sellers, and final consumers to quickly and intuitively grasp the grade and characteristics of coffee beans, coffee beans usually undergo a standardized and normalized evaluation process before entering the market, and are then assigned corresponding grades based on the evaluation conclusions, and finally sold at prices corresponding to those grades.

The grading criteria adopted by different countries are not consistent. For example, Ethiopia divides grades based on the proportion of defects in coffee beans, most producing areas in Central and South America use planting altitude as the grading standard, while producing areas that use markings such as AA and AB mainly consider the particle size of coffee beans.

This is indeed how Kenya's grading method works, but in addition to bean size, the official system also incorporates other indicators such as shape and hardness into a comprehensive evaluation. Arranged from highest to lowest score, the grades are: AA, AB, C, PB, E, TT, T, MH/ML.

AA: This is the highest grade in Kenya's official classification, requiring coffee beans to have a screen size between 17 and 18 mesh.

AB: The grade second only to AA, requiring coffee beans to have a screen size between 15 and 16 mesh.

PB: This is a special grade. The coffee beans in this grade have a round appearance and are usually called peaberries.

E: Similar to PB, the coffee beans in grade E also have a rather special appearance, being larger than ordinary beans at about 21 mesh, commonly known as elephant beans.

C: The qualifying standard for grade C is coffee beans with a screen size between 13 and 14 mesh.

TT: Refers to lighter coffee beans blown out by the blower from the AA and AB grades.

T: Similarly, grade T refers to lighter coffee beans blown out by the blower from grade C.

MH/NL: Coffee beans in this grade are products that have not undergone fine processing and are of relatively lower quality. They are usually not exported and are sold only within Kenya.

The above is Kenya's official coffee grading system. In addition to these official grades, as Front Street mentioned at the beginning, there are also markings on the market such as AA+, AA TOP, and FAQ. They do not belong to the national official grading, but are secondary classifications made by green bean traders for AA-grade coffee beans.

The secondary grading standards of different traders are not the same, but it is not hard to infer that they make judgments based on performance at the drinking level, such as flavor, layering, and mouthfeel. For example, if a certain bean has a particularly outstanding flavor and very bright acidity, standing out among AA-grade beans, it can be labeled AA+ or AA TOP to distinguish it from other AA-grade coffee beans.

However, it should be noted that coffee beans graded AA+ or AA TOP are not necessarily superior to AA-grade beans. These are grades added by green bean merchants themselves, and it is inevitable that commercial considerations are mixed in. Moreover, as Front Street said earlier, every exporter has its own evaluation standards, so the results also vary.

Of course, there are also green bean merchants who do not participate in this kind of grading. They believe that the coffee beans they sell are already the best choice after careful selection and that there is no need to use additional labels to set them apart from other beans. For example, the Kenya Little Tomato currently listed by Front Street on Tmall and Taobao is the final choice Front Street settled on after cupping dozens of Kenyan beans. It is an AA-grade coffee bean from Kenya's Asaliya washing station.

Front Street Coffee: Kenya · Asaliya

Region: Thika

Washing Station: Asaliya Washing Station

Altitude: 1,550–1,750 meters

Varieties: SL28, SL34

Processing Method: Washed

Flavor: Smoked plum, cherry tomato, yellow sugar, black plum

In order to fully present the bright acidity and caramel texture of Kenyan coffee, Front Street chose a roasting profile with a longer development time. In the end, the roast level of this Kenya · Little Tomato landed at a medium-light degree. The extraction parameters are as follows: 15 g dose, 1:15 coffee-to-water ratio, grind setting of 10 on the Ek43, 75%–80% passing through a No. 20 sieve, water temperature 92°C, V60 dripper, extraction time 2 minutes.

The Kenyan coffee brewed according to this set of parameters has just the right concentration, allowing you to clearly perceive the bright acidity of cherry tomato and smoked plum, the sweetness of caramel, and the long finish like oolong tea. It is well worth trying~

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