SL9 (provisional working name)

The story of SL9 is one of the most compelling mysteries in modern specialty coffee, representing a near-lost genetic lineage that has found a surprising sanctuary in the Peruvian Andes. While the name 'SL9' references the single-tree selection program conducted by Scott Agricultural Laboratories in Kenya during the 1930s, the variety’s journey from East Africa to the remote Inkawasi Valley in Cusco remains undocumented. For decades, local farmers cultivated this plant under the name 'Inca Gesha' or 'Gesha Inca,' unaware that their crop was not the famous Gesha variety, but rather a distinct, rare cultivar of Ethiopian legacy origin.

In the original Kenyan context, the SL09 selection was largely abandoned by researchers. According to historical records from the Coffee Board of Kenya, the original SL09 was characterized as a shy bearer—meaning it produced low yields—and was found to be highly susceptible to Coffee Berry Disease. Consequently, it was dropped from commercial breeding programs and largely disappeared from global records, with only isolated traces of its existence appearing in historical variety trials in Malawi. Its survival and subsequent proliferation in Peru represent a botanical anomaly that has only recently been brought to light through modern genetic testing.

Independent genetic analysis commissioned by roasters and producers, including work by RD2 Vision and World Coffee Research, has confirmed that the Peruvian 'Inca Gesha' is genetically consistent with the original Scott Labs SL09. This revelation has allowed the industry to move away from the misleading 'Gesha' moniker, adopting 'SL9' as a provisional working name to accurately reflect its lineage. Despite the name, researchers emphasize that the plant contains no Gesha in its genetic composition, marking it as a unique member of the Ethiopian Legacy group.

In the field, SL9 is a tall-growing plant characterized by broad leaves and distinct copper-colored tips on new growth. It thrives at extreme elevations, with many of the most notable lots sourced from farms situated between 1,700 and 2,400 meters above sea level. These high-altitude conditions are critical to the variety's performance; the cool temperatures significantly slow the maturation of the coffee cherries, which allows for the development of complex sugars and aromatic compounds that define the cup profile.

For the drinker, SL9 is celebrated for its exceptional cup clarity, refined sweetness, and intense floral and fruit-forward aromatics. Roasters and sensory professionals often describe the profile as crisp and structured, possessing a depth and velvety mouthfeel that distinguishes it from more common cultivars. Its sensory characteristics are often compared to the high-quality profiles associated with Kenyan coffees, which is consistent with its historical roots in the Scott Labs selection program.

Producers in the Inkawasi Valley continue to cultivate SL9 because of its proven ability to produce high-quality coffee in their specific microclimates. While the variety was historically considered a 'shy bearer' in Kenya, the unique environmental conditions of the Peruvian Andes appear to support its viability. The ongoing collaboration between geneticists, local communities, and the specialty coffee industry aims to better understand how this variety should be represented and preserved, ensuring that its history is documented as accurately as its flavor profile.