Kenya’s coffee grades — AA, AB, PB, C, E, TT, T — sort beans by screen size, density and defect count. They describe the bean, not the flavour in the cup. AA is the largest screen (18); E stands for Elephant and is larger still; PB is peaberry, a cherry that produced one round seed instead of two, which is a shape rather than a size rank. Grading happens after the coffee is already grown and processed, so a high grade cannot make a bad lot taste good. What actually drives Kenyan cup character is the varieties planted (SL28, SL34, Ruiru 11 and Batian), the highland volcanic ground they grow in, and the washed processing almost every Kenyan mill uses.
Table of Contents
Corrections to an earlier version of this page
This page previously got several things wrong, and it is worth naming them rather than quietly editing them out.
- It listed E among the “smaller beans”. E is Elephant — the largest beans in the Kenyan system. The Nairobi Coffee Exchange’s own grade list defines E as “very large beans”.
- It treated PB as a size rank between AB and C. PB is peaberry: “small round beans formed when only one seed develops in the cherry” (Nairobi Coffee Exchange). It is a fruit-set outcome, not a position on a size ladder.
- It said grading “significantly influences their taste and quality”. That reverses cause and effect. The exchange describes grading as sorting “by screen size, defect count, and quality” — quality is an input to the grade, not a product of it.
- It called SL28 and SL34 disease-resistant. They are the opposite. World Coffee Research rates SL28 as “low resistance/susceptible” to coffee leaf rust and “susceptible” to both coffee berry disease and nematodes, and gives SL34 the same three ratings. Their susceptibility is exactly why Kenya bred Ruiru 11 and Batian, neither of which this page used to mention.
- It cited a “National Geographic Article” on Kenyan coffee flavour, an International Coffee Organization “report”, and a “Fair Trade Article” — all three links pointed at bare homepages, not at any article making those claims. They have been removed and replaced with sources that say what this page says they say.
The Kenyan grade table, as the auction defines it
| Grade | What it means |
|---|---|
| AA | Screen 18. Largest standard bean size; usually the highest auction prices. |
| AB | Screen 16–17. The most commonly traded grade. |
| PB | Peaberry. One round seed instead of two. |
| C | Smaller beans, often blended or sold regionally. |
| E | Elephant. Very large beans. |
| TT | Lighter, less dense beans separated during grading. |
| T | Small or light beans. |
| MH / ML | Mbuni — dry-processed (unwashed) coffee, a different flavour profile. |
A separate class number, assigned on cup, is what actually rates the liquor. Two AA lots from neighbouring washing stations can cup very differently. So “AA” on a bag tells you the beans are big and were carefully sorted; it does not promise the cup, and it is not a reason to pay more on its own.
The varieties, and why Kenya keeps breeding new ones
Kenya grows almost exclusively Arabica. Four varieties account for most of it, and they split cleanly into the old ones people prize and the new ones that survive.
- SL28 — selected in 1935 at Kenya’s Scott Agricultural Laboratories from “Tanganika Drought Resistant” material with a Bourbon-like background. Tall, low-yielding, and susceptible to leaf rust, coffee berry disease and nematodes (World Coffee Research).
- SL34 — selected from a single tree on Loresho Estate at Kabete, labelled “French Mission”, with a Typica-like background. Tall, medium yield, “exceptional cup quality” but “highly susceptible to coffee berry disease” (World Coffee Research).
- Ruiru 11 — released in 1985 by Kenya’s Coffee Research Foundation (now KALRO) after the 1968 CBD epidemic. Compact, very high yielding, “highly resistant” to leaf rust and “resistant” to coffee berry disease (World Coffee Research).
- Batian — released in 2010 by the same institution. Tall, very large beans, resistant to coffee berry disease and intermediate against leaf rust; WCR describes it as unusually well suited to smallholders for combining tall stature with disease resistance (World Coffee Research).
Arabica reached Kenya through French Spiritan missions: seed from La Réunion was planted at Bura in the Taita Hills in 1893, and seedlings from Bura went to the Saint Austin mission near Nairobi in 1899, from where they spread to settler farms (World Coffee Research). The “French Mission” label on the tree that became SL34 is a direct descendant of that introduction.
Where it grows
Coffee grows mainly in Kenya’s central highlands and the Rift Valley — Nyeri, Kirinyaga, Murang’a, Kiambu, Embu and Meru counties among others — at roughly 1,400–2,100 m in volcanic soils, with distinct wet and dry seasons (Nairobi Coffee Exchange). Altitude and soil are the levers that matter here: slow cherry development at elevation is what builds the acidity Kenyan coffee is bought for.
How Kenyan coffee is sold — and what changed in 2023
Most Kenyan coffee moves through cooperatives and the auction. The USDA Foreign Agricultural Service’s Kenya Coffee Annual reports that about 550 cooperatives market over 80 percent of Kenya’s coffee, and that the Nairobi Coffee Exchange, a spot market operating since 1935, handles over 90 percent of coffee sales; the remainder goes through direct contracts between buyers and producers’ agents.
In July 2023 the Kenyan government abolished marketing agents and banned businesses from holding multiple licences along the value chain. Payments for coffee sold through the exchange now run through a Direct Settlement System managed by the Cooperative Bank of Kenya; broker licensing moved to the Capital Markets Authority; milling licensing moved to county governments. USDA reports that the reforms also ended the input, extension and certification programmes the de-licensed agents used to run, and that several large millers stopped operating under the new licensing rules (USDA FAS, Kenya Coffee Annual, report KE2024-0003). If you buy Kenyan coffee, that is the machinery your bag came through.
What Kenyan coffee tastes like — and what nobody can promise you
Washed Kenyan Arabica is bought for high, structured acidity and a heavy body; blackcurrant is the descriptor traders reach for most often. We have not cupped a panel of Kenyan lots ourselves, so this page will not publish tasting scores or invent notes for a specific coffee. Treat the roaster’s own cupping notes on the bag as the claim that actually applies to what you bought — and note that Ruiru 11 and Batian lots, bred for survival rather than for the cup, can taste noticeably different from an SL28/SL34 lot from the same county.
Brewing it
Start at 55 g of coffee per 1 litre of water — about 1:18 by weight. That is the standard brew ratio specified in SCA Standard 310-2021, Home Coffee Brewers, which defines it as “55 g of coffee per 1.000 kg of water” and requires brewers to print that ratio in their instructions. Stronger means more coffee, not less: at 1:15 you are using more grounds per litre than at 1:18, not fewer. Note that a “cup” in coffee measurement is 6 fl oz, not 8 — most kitchen confusion about dosing starts there.
For water temperature, see our page on the best temperature for French press coffee, which states the range with its source rather than repeating it here. Pour-over suits Kenyan coffee’s acidity; a medium-fine grind and a steady, slow pour is the whole technique. A gooseneck kettle with a built-in thermometer makes the pour and the temperature controllable at the same time.
Affiliate disclosure: the product link in this section is a paid link. As an Amazon Associate I earn from qualifying purchases. It costs you nothing extra. We have not tested this kettle; it is listed because a gooseneck spout and a built-in thermometer are the two features that matter for pour-over, not because we compared it against others.
Barista Warrior gooseneck kettle with thermometer on Amazon
Buying Kenyan coffee
- Roast date, not a “best before” date. If the bag will not tell you when it was roasted, that is the answer.
- A named region, cooperative or washing station — Nyeri, Kirinyaga, Embu and so on. “Kenya AA” alone tells you only the screen size.
- Variety, if it is stated. SL28 and SL34 are what most specialty buyers are chasing; Ruiru 11 and Batian are increasingly common and are not a defect.
- Certification claims should name the scheme and, ideally, the certificate holder. A certification logo without a named scheme is a design element.
For neighbouring origins with very different profiles, see our pages on Ethiopian coffee and Ugandan coffee, and on roast levels if you are deciding how dark to buy.
