Arabica · Coffee Variety
SL28
SL28 was selected in 1935 by Scott Agricultural Laboratories in Kenya from a drought-tolerant Tanganyika population — and became one of the most celebrated quality varieties on earth. It defines the Kenyan cup: blackcurrant, tomato-vine brightness, grapefruit, and a juicy, wine-like structure that auctions reward year after year.
The variety's deep root system handles drought remarkably well and trees remain productive for decades — some original plantings still bear. Its weakness is disease: no rust or CBD resistance, which is why Kenya pairs it with resistant Ruiru 11 and Batian in modern plantings.
SL28 at a glance
| Species | Arabica |
|---|---|
| Lineage | Scott Agricultural Laboratories selection (Kenya, 1935) from Tanganyika drought-resistant stock |
| Plant stature | Tall, broad leaves, bronze tips |
| Yield potential | Moderate |
| Disease resistance | Susceptible to rust and CBD; excellent drought tolerance |
| Optimal altitude | 1,400–2,100 m |
| Bean size | Large |
| Cup profile | Blackcurrant, grapefruit, tomato-vine acidity, wine-like body — the classic Kenya profile |
Where SL28 is grown
SL28 — frequently asked questions
Why does SL28 taste of blackcurrant?
The variety's chemistry combined with Kenya's high-potassium volcanic soils and double-washed processing produces high concentrations of the fruit acids and thiols cuppers read as blackcurrant. Terroir and process amplify a genuinely varietal trait.
What does 'SL' stand for?
Scott Agricultural Laboratories, the colonial-era research station (now NARL) near Nairobi that numbered its experimental selections — SL28 and SL34 are simply selection numbers 28 and 34.
Can SL28 grow outside Kenya?
Yes — plantings exist in Uganda, Zimbabwe, and Latin America — but the full auction-grade profile has proven hard to replicate away from Kenyan altitude, soil, and processing infrastructure.
Sourcing SL28? Volcana Coffee grows and exports high-altitude Catimor, Typica, and washed Fine Robusta from the Bolaven Plateau, Laos — with SGS-inspected quality and full export documentation.
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