Kenya Coffee AA, PB, SL28 Taste Guide

Kenya Coffee AA, PB, SL28 Taste Guide
Source Ivica Cvetanovski

Kenyan coffees taste sweet and acidic, and are often compared to tart-tasting fruit like blackberries and currants.

The most common flavor descriptors for Kenyan coffees are: black currant, lemon, red grape, lime, and blackberry.

This guide helps you understand the terminology used to describe subtle differences in Kenyan coffees across variety, region, and grading system. The next time you’re considering a bag of Kenyan coffee, you will know what to expect.

History and Terroir of Kenyan Coffees

Kenya is one of the most iconic specialty coffee producing regions. Thought to have been first introduced by French missionaries from the island of Bourbon, most Kenyan coffees are a descendant of the bourbon varietal, known for its sweetness and chocolatiness.

Kenyan coffee is grown in high, volcanic soil, mostly between Mount Kenya and Nairobi. Because Kenyan coffees are grown at high elevation, coffee plants grow in a colder environment. The colder temperature causes the plant to grow more slowly and for the fruit of the coffee cherry to take more time to develop. Combined with fertile, volcanic soil, Kenyan coffee cherries are dense, sugary fruits that become sweet, fruity tasting coffees in liquid form. It’s this combination in terroir that makes Kenyan coffee sweet and special.

Kenyan Coffees are Washed

Most Kenyan coffees are washed, because coffee production in Kenya is centralized.

Until 2021, Kenyan export standards required coffees to be wash processed. Even with the requirement lifted, however, the centralized nature of coffee production in Kenya makes it difficult to produce anything outside of washed coffees.

Smallholder Kenyan farmers with land below a certain size are legally required to process coffees with a society or co-op, which are then required to dry and husk coffees at one of eight drying mills.

Because coffee drying is centralized within society factories (the equivalent of washing stations), there are often capacity issues at the drying level. This has led to a recent trend of “double washing” or “double fermentation”. Because coffee drying factories lacked capacity (space for coffees on drying beds), co-ops relied on a secondary water tank to store coffees that had already been pulped and washed – acting as an intermediate waiting area before the final drying destination.

Because Kenyan coffees are predominantly washed, you should expect a cleaner profile highlighting sweet and acidic characteristics. If you’re able to get your hands on a natural processed Kenya, that’s a coffee worth trying.

Kenyan Coffee Varieties

  1. SL28
  2. SL34
  3. K7
  4. Ruiru 11
  5. Batian

SL28 | Scott Labs 28

The British government founded Scott Agricultural Laboratories in 1922, which left Kenya with two of its most prized and notable coffee varieties: the SL28 and SL34. Both varieties are thought to be complex with fruit and spice notes throughout.

SL28 are known for their blackberry profile: sweet with berry-like tartness.

SL28’s are also thought to be tomato-like depending on the perception of sugars and acids in the coffee.

SL34 | Scott Labs 34

There aren’t very perceivable differences between SL34 and SL28 varieties, other than the way they’re grown. SL34 varieties typically require more nutrition than SL28, but both contribute to a renowned cup profile. SL28 and SL34 together comprise ~80% of Kenyan coffees exported.

K7 | Coffee Research Institute

The K7 variety is a disease resistant crop introduced by the Coffee Research Institute, a native research foundation that took over the work from Scott Labs in the mid 20th century.

The K7 variety grows at lower altitudes, making it less prized as the SL28 and SL34 varieties for roasters, but are seen as more commercially viable crops for farmers.

Ruiru 11 | Coffee Research Institute

The Ruiru 11 is a variety crossbred from robusta plants. Similar to the K7, it’s known for its low height (dwarfism), making it easier to pick and resistance to coffee borer disease.

Batian | Coffee Research Institute

Batian is a modern variety introduced by the Coffee Research Institute that’s bred from pure Arabica. Thought to have the same disease resistant benefits as Ruiru and K7, while still expressing flavor qualities similar to the SL28 and SL34, the Batian variety is a large berry that seems to hold promise as Kenya’s next high-yield specialty coffee.

Kenyan Heirloom – “French Mission”

The Kenyan Heirloom variety most closely resembles the bourbon variety brought over by the French in the 19th century. Kenyan Heirloom varieties are widespread and have chocolatey qualities like their genetic ancestor.

Kenyan Coffee Grades | AA, AB, PB

Kenyan coffee is categorized by grade (related to size) and class (a quality scale from 1 to 10, with one being the worst and ten being the best) .

In general, Kenya AA and PB are seen as the most prized coffee grades and are most sought after by roasters.

Source Padre Coffee

Kenya AA

Kenya AA are large beans that grow at high elevations. Kenya AA coffees tend to be light-bodied and reminiscent of blackberries and black currants. They have a floral aroma and a mild, crisp acidity, like that of cold grapes.

Kenya AB

Kenya AB mixes beans from grades A and B. Because A beans are slightly larger than B, this can lead to less consistency in the roast profile, leading roasters to prefer the more carefully sorted AA beans over AB.

Despite being more abundant, Kenya AB can exhibit the same floral aroma and sweet, fruity flavor as AA.

Kenya PB | Peaberry

Kenya PB (short for peaberry) describes coffee cherries with one single seed as opposed to two or three. Peaberries are a naturally occurring genetic mutation that results in a single rounded seed as opposed to two semicircular seeds in one coffee cherry.

While there’s debate as to whether peaberries are superior to other coffee beans (the rounder shape may make the beans more conducive to roasting), it’s not obvious that they are superior in terms of flavor.  

Peaberries are rarer than their double seeded counterparts, occurring approximately 10% of the time. As a result, peaberries are also harder to sort (they are first sifted by density and then sorted by hand). The additional labor can result in higher prices, which can be passed onto the consumer in the form of more expensive beans.

The bottom line is that peaberries are a novelty in the specialty coffee world and are amongst the rarer grades of Kenyan coffee beans.

Kenya E, C, TT, MH

Kenya E refers to large, single seed beans that split while handling – they’re peaberries that fall apart while processing, milling, or drying. They’re classified as Kenya E, because of their “elephant ear” appearance.

Grades outside of Kenya AA, AB, and PB are often thought of defects and should be avoided.

The full list of coffee grades are as follows:

  • Kenya E (Elephant Bean)
  • Kenya PB (Peaberry)
  • Kenya AA
  • Kenya AB
  • Kenya C
  • Kenya TT
  • Kenya T
  • Kenya MH/ML

How to Choose Kenyan Coffee Varieties

Many Kenyan varieties are often blended together, so it can be difficult to acquire single-origin lots of Batian or Ruiru coffees.

However, if you’re looking at a bag of Kenya AA SL28 or SL34, you expect a floral cup with notes of tart berries and spices from one of the most iconic coffee growing regions in the world.