New Wild Coffee Variety Discovered in Africa: Hope for Enhanced Heat Resistance in Arabica Coffee Varieties

A recent research report from the Potsdam Institute for Climate Impact Research indicates that climate change will lead to a decline in both the yield and quality of specialty coffee in Ethiopia. To help the global coffee supply chain keep pace with a changing climate, coffee cultivation researchers are continuously hunting for unknown coffee varieties for research and hybrid breeding, hoping to develop plants that can withstand climate change while still producing high-quality cherries.

On April 19th, Aaron Davids, an expert from the Royal Botanic Gardens, published a research paper titled "Arabica-like flavour in a heat-tolerant wild coffee species" in the leading international journal Nature Plants.

The paper reports that researchers discovered a little-known wild coffee variety in the tropical rainforests of Sierra Leone. Its leaves are noticeably narrower than those of Arabica, so the species was named Coffea stenophylla, or narrow-leaf coffee. The research found that narrow-leaf coffee is heat tolerant and better able to withstand heavy rainfall, and that its flavor resembles that of high-quality Arabica beans. This wild species could help breed coffee trees that adapt to climate change without sacrificing cup quality.

As Davids analyzed in the report, this wild coffee species is native to Guinea, Sierra Leone, and the Ivory Coast, and was exported to Europe before the 20th century. Many historical documents attest to narrow-leaf coffee's excellent aroma. It was only with the rise of Robusta in the early 20th century that it fell into oblivion. After that, no sensory information about it was published, and it was presumed extinct in Guinea and Sierra Leone until being rediscovered in Sierra Leone in 2019.

After the 2019 rediscovery, researchers began cultivating the variety in 2020 on Réunion in the Mascarene Islands. Once samples of the beans were obtained, standard sensory evaluation comparisons were run against two Arabica samples and one Robusta sample. The results confirmed that narrow-leaf coffee has a flavor profile similar to that of high-quality Arabica.

Beyond the sensory comparisons, Davids and his team modeled the variety's climate adaptability. They found that narrow-leaf coffee can grow under the high-temperature conditions Robusta tolerates — and even hotter — with an average tolerable temperature of 24.9°C, at least 6°C higher than what Arabica varieties can withstand. The report points to real potential for improving Arabica's resilience to climate change.

FrontStreet Coffee Recommendation

Until heat-tolerant hybrids like stenophylla reach our cups, Ethiopia remains the gold standard for distinctive coffee — it is, after all, the birthplace of Arabica and home to thousands of native varieties. To taste that heritage, FrontStreet Coffee's washed Yirgacheffe delivers crisp jasmine florals and bright citrus acidity in a clean, tea-like cup, while the FrontStreet Sidamo natural Hambella flower-queen lot — 21 days of drying on raised beds — offers fermented wine notes, florals, citrus, and mango with a thick, lingering body. For a look at where wild Ethiopian genetics still thrive today, the FrontStreet Kaffa Forest coffee, grown semi-wild at 1400-2100 meters under forest shade, shows white floral aroma, bright lemon acidity, sweet orange and bergamot, and a green-tea-like mouthfeel — a living reminder of just how much flavor diversity the coffee world stands to protect.