SL28 and SL34
also: SL-28, SL-34, Scott Labs varieties
Kenyan-selected arabica varieties behind the classic blackcurrant brightness and structured acidity of Kenyan coffee.
SL28 and SL34 are two arabica varieties selected at Scott Agricultural Laboratories in Kenya in the 1930s, which is where the “SL” comes from. They were chosen for quality and drought tolerance and went on to define the flavor reputation of Kenyan coffee.
SL28 is the more celebrated of the pair, with bourbon-related heritage. At altitude it produces an intensely bright, juicy cup, the source of Kenya’s signature blackcurrant and tomato-leaf notes with a structured, mouth-watering acidity. SL34 also traces to the Bourbon group, tolerates higher rainfall, and tends to be a touch heavier and less piercing in the cup.
Why it matters: these two varieties, often grown side by side and blended at the washing station, are a big part of why Kenyan coffee tastes so distinctive and structured. Both are low-yielding and susceptible to disease, but their cup quality keeps them planted. See kenya and varietals-deep-dive.