— Journal · Origin · 8 min read
Why SL28 still matters.
A 90-year-old varietal that refuses to be replaced. Inside the cultivar that defined modern Kenyan coffee — and why we still build our best lots around it.
Walk through almost any serious cupping lab in the world, and the name comes up within minutes: SL28. Bred in the 1930s by Scott Agricultural Laboratories just outside Nairobi, it is one of the oldest named Arabica varieties still in commercial production — and nearly a century later, it remains the variety Kenyan farmers reach for when nothing less than exceptional will do.
A deliberately difficult plant
SL28 was never bred for ease. It is low-yielding, demanding of altitude, and susceptible to disease in a way that modern, more "forgiving" cultivars are not. On paper, it makes no economic sense for a farmer to plant it over a hardier, higher-output alternative.
And yet, across our partner washing stations in Nyeri and Kirinyaga — at 1,700 to 1,800 metres above sea level — farmers keep SL28 in the ground, season after season. The reason is simple: nothing else in the cup comes close.
What you actually taste
At altitude, in volcanic, mineral-rich red soil, SL28's deep root system draws out a density of flavour that lower, easier-growing cultivars simply cannot match. Combined with our fully washed processing, the result is the signature Baobab cup: bright acidity up front, a core of dark cocoa, and a clean, lingering citrus finish.
It is wine-like in its structure — layered rather than flat, with an acidity that lifts the cup instead of souring it. That is the SL28 signature, and it is the single clearest reason Kenyan Arabica built its global reputation in the first place.
Why we keep choosing it
We could roast a higher-yield, lower-cost varietal and nobody outside a cupping table would notice the swap on a spec sheet. But our farmers would notice the pay cut, and you would notice the flattened cup. So every season, we pay a premium for SL28 lots — not out of nostalgia, but because low yield and high difficulty are exactly the trade-offs that produce a coffee worth drinking black.
We also work alongside SL34, Ruiru 11 and Batian where they earn their place in a blend — but SL28 remains the backbone of what "Baobab" tastes like. Ninety years on, it still hasn't been replaced, and we don't expect that to change.