What is the SL-28 coffee varietal?

SL-28 is one of the most celebrated cultivars in specialty coffee, selected by Scott Labouratories in Kenya in the 1930s from material believed to originate from drought-resistant trees in Tanzania. It's associated with some of the most acclaimed Kenyan coffees ever produced.

A tall, large-leaved plant producing bold beans, SL-28 at high altitude in Nyeri, Kirinyaga, and Murang'a delivers something genuinely distinct: intense, layered acidity - blackcurrant, grapefruit, tomato - pronounced sweetness, and a complexity that's made it a reference point in specialty coffee globally. When people talk about what makes Kenyan coffee special, they're largely talking about SL-28.

The variety is highly susceptible to leaf rust, which limits its viability without significant disease management. Kenya's continued cultivation of SL-28 despite this vulnerability is a direct reflection of the cup quality premium it commands - a premium that justifies the cost. Plantings now exist outside Kenya - in Colombia, Panama, parts of Central America - though results vary considerably compared to the home context.