Kenyan Coffee: A Guide to AA Grades, SL28 and That Blackcurrant Flavour

Kenyan coffee is one of the easiest to recognise in the cup. It's bright and juicy, often with blackcurrant, grapefruit or tomato-like sweetness, and a lively acidity that makes it a favourite with speciality roasters. Here's what makes it taste that way, and the Kenyan coffees that have been in our boxes.

Where coffee grows in Kenya

Most Kenyan coffee grows in the highlands around Mount Kenya and the Aberdare range, between about 1,400 and 2,000 metres. The best-known counties include Nyeri, Kirinyaga, Kiambu, Murang'a and Embu. The deep red volcanic soils and cool nights slow the cherries as they ripen, which helps build the sugars and acidity Kenyan coffee is known for.

Who grows it

Kenya's coffee comes mainly from smallholders. Farmers with a few hundred trees each pick their ripe cherries and deliver them to a local "factory" – the Kenyan name for a washing station – run by their co-operative. Each factory processes cherry from hundreds or thousands of farmers, and its name is often what you'll see on the bag (Thimu, below, is one). There are also larger private estates.

SL28, SL34 and the other varieties

Two varieties give Kenyan coffee much of its character:

• SL28 – bred in Kenya in the 1930s and prized for its intense, complex fruit and acidity.
• SL34 – a close relative that does well at higher, wetter sites, with a heavier body.

You'll also see Ruiru 11 and Batian, newer Kenyan varieties bred to resist coffee leaf rust and berry disease. Many lots are a mix.

What "AA" means

Kenyan coffee is graded by bean size. AA is the largest grade, followed by AB, with PB (peaberry) for the small, round single beans that grow one to a cherry. AA lots usually sell for the most, but size isn't a guarantee of flavour: a great AB can beat an average AA. Grades like "AA Plus" are sellers' labels for their best AA lots rather than an official grade.

How it's processed

Almost all Kenyan coffee is washed. The cherries are sorted, pulped to remove the skin, fermented in tanks, washed in clean water and often soaked again before drying slowly on raised beds for one to two weeks. This careful, clean processing is a big part of why Kenyan coffee tastes so bright and defined.

What Kenyan coffee tastes like

Expect a juicy, fruit-forward cup: blackcurrant, redcurrant, grapefruit, orange or tropical fruit, sometimes a savoury, tomato-like sweetness, with a medium to full body and a crisp finish. Lighter roasts show the fruit best.

Kenyan coffees that have been in our boxes

Kenya Rioki AA (Kiambu)

Grown by around 3,000 smallholders around Rioki in Kiambu County, at about 1,600 metres. SL28 and SL34, fully washed. A complex, juicy cup with tropical fruit, stone fruit and citrus, turning to baking spice as it cools. Roasted for us by Atkinsons Coffee Roasters.

Kenya Thimu AA (Mount Kenya)

From the Thimu factory on the southern slopes of Mount Kenya, run by the Baragwi Farmers' Co-operative, with around 3,000 member farmers. "Thimu" means "proverbs". SL28 and SL34, washed, fermented for 12–18 hours and dried on raised beds for about two weeks. Sweet blackcurrant, tamarillo and maple syrup with a creamy body. Roasted for us by Bailies Coffee Roasters.

Kenya Dormans AA Plus (Nyeri)

A top-grade AA lot from the high plateaus of Nyeri County. Berry notes, a medium body, lively acidity and a creamy finish with a hint of vanilla. Roasted for us by Wogan Coffee in Bristol.

How to brew Kenyan coffee

Kenyan coffee shines as filter: a pour-over, AeroPress or cafetière keeps the fruit and acidity clear. Try 15g of coffee to 250ml of water just off the boil. If it tastes too sharp, grind slightly finer or brew a little longer; if it tastes flat, go a touch coarser. It also makes a fruity, bright espresso, and works well with a little milk. For more origins, see our guide to Ethiopian coffee and South American coffee, or meet our roasters.