What are Coffee Bean AA and AAA Grades Based On? What Are Their Characteristics?

As any observant coffee lover has probably noticed, many commercially sold coffees carry the "AA" suffix. It is especially common on beans from Kenya — Kenya Nyeri AA, Kenya Kirimiri AA, and so on.

And it is not just Kenya. Beans from countries such as Tanzania and Uganda carry the same suffix. Which raises the question: what does AA actually mean, and why do these countries put so much emphasis on it?

What Does the AA Suffix on Coffee Beans Mean?

The "AA" suffix is a grade designation. Because coffee is an agricultural product rather than an industrial one, quality varies considerably from lot to lot. To standardize quality, producers need a system for separating the good from the mediocre — and that system is grading. So when you see "AA" attached to beans from certain countries, it tells you that the country grades its coffee by bean size.

Two points are worth clarifying here. First, size is not the only basis for grading coffee — other systems classify beans by defect count, altitude, and more, with each producing country applying whichever approach suits its conditions. FrontStreet Coffee will cover those in another article.

Second, not every size-based system uses uppercase English letters as its labels. Identifiers like AA and AB belong to a grading unit developed by the British, and most countries using them are former British colonies. Colombia, for instance, also grades by size but uses its own labels: "Supremo" and "Excelso."

That said, Kenya is the most famous example of size-based grading, largely because the Kenyan government takes its coffee industry extremely seriously and enforces very strict quality requirements. So let's walk through Kenya's size grading system.

Kenyan Coffee Bean Grades

AA: Beans that pass through a screen size of 17-18.

AB: Beans between screen size 15-16.

C: Grade C beans fall between screen size 12-14. Because of their small size, they are generally not considered specialty grade.

PB: Rare round green beans; short for Peaberry.

E: Short for Elephant, referring to elephant beans. Note that these are not the elephant bean varieties within the coffee species (Maragogipe, Pacamara), but abnormally developed beans similar to peaberries. They form when two seeds become intertwined during development, producing what looks like a single, very large, swollen bean. They exceed screen size 18 and are extremely rare.

TT: Grade TT consists of lightweight beans blown out of AA and AB lots by air screeners.

T: Grade T consists of lightweight beans blown out of Grade C lots by air screeners.

MH/ML: These two lower grades are not processed by the Kenyan washed method. They are typically consumed domestically and not exported.

The Limitations of Size-Based Grading

The list above is Kenya's official national grading system, and within it AA clearly represents the highest size grade. However, as FrontStreet Coffee discussed in a previous article, "Does Coffee Bean Flavor Relate to Size?", size-based grading has real loopholes.

Bean size does not directly determine cup quality. Here is an example coffee professionals often cite: when the same variety is grown at 900 meters and at 1700 meters, the beans may end up the same size, but the coffee from 900 meters will never taste as good as the one from 1700 meters. The growing environment is one of the main factors shaping flavor development in the bean.

Kenya's Quality-Based Grading System

In an era when bigger was assumed to be better, size grading was naturally the mainstream approach, and most traditional coffee-producing countries adopted it. But once the specialty coffee movement took hold, people began to understand the factors that actually shape flavor, and entirely new grading systems emerged. Kenya kept pace: local coffee research institutions and green coffee traders apply their own quality-based methods as a second grading pass on Kenyan AA and AB coffees.

This system is called the Kenyan Classification Procedure by Quality Assessment, developed by the Kenyan Coffee Research Foundation. It evaluates beans comprehensively across three dimensions: green bean quality, roasted bean quality, and cupping quality.

TOP, Plus (+), and FAQ are the labels used in this secondary grading. Beans that earn the corresponding scores carry the suffix on their original grade — Kenya AA TOP, Kenya AA+, and so on. These mark the outstanding performers within AA or AB lots, while FAQ indicates beans with minor defects that do not affect the flavor.

Finally, it is worth knowing that because this system is not an official Kenyan certification, most Kenyan beans on the market today are still sold primarily under conventional size grades (AA, AB).

FrontStreet Coffee Recommendation

If the AA discussion has you thinking about trying graded beans from another classic origin, FrontStreet Coffee's washed Colombia Huila is an excellent starting point. Huila, in the southern Central Cordillera, is Colombia's most famous specialty coffee region — hill country at elevations above 1500 meters, fed by the confluence of the country's most important rivers and their abundant water. Roasted medium-dark, this bean highlights the sweet aroma of dark chocolate and nuts, with moderate crema and a full body. It performs beautifully as pour-over or French press, and it is equally at home in a moka pot or espresso machine for Americanos and lattes.

For something more adventurous, try FrontStreet Coffee's Colombia Fenjixian Estate Sidra, processed by anaerobic natural fermentation — a low-oxygen fermentation in a pressure-resistant stainless tank where temperature, time, and pH are precisely controlled. The result is an abundance of tropical fruit aromatics: passion fruit, grape, apricot, and dried fruit, layered and intensely fragrant when brewed as pour-over or cold brew at a medium-light roast.