A forgotten species of coffee that grows at high temperatures, that has superior flavor, could help futureproof the coffee industry against climate change, scientists claim.
The scientists believe Coffea stenophylla – a rare and threatened species from West Africa – could be important as arabica coffee is threatened by changes in world weather pattens. It has the unique combination of tolerance to high temperatures and a superior flavor.
Dr. Aaron Davis, head of coffee research at Kew said, “This is a once-in-a-lifetime scientific discovery – stenophylla - could ensure the future of high-quality coffee. Future-proofing the coffee supply chain to deal with climate change is vital.” Results from an independent, professional tasting with panellists from Nespresso & Jacobs Douwe Egbert suggest the flavor of stenophylla is like high-end arabica.
In a paper published in Nature Plants, scientists at Kew, along with others at University of Greenwich, CIRAD and others working in Sierra Leone, revealed the results of an in-depth study of the species. They claim its unique qualities mean it could soon be grown commercially, but in much warmer places than arabica. It also has the potential to be used as a breeding resource, to produce new, climate-resilient coffee crops for global consumption.
Dr Davis said, “Future-proofing the coffee supply chain to deal with climate change is vital. To find a species that flourishes at higher temperatures and has an excellent flavour is a once in a lifetime scientific discovery.”
Dr Davis and Professor Jeremy Haggar from Greenwich University travelled to Sierra Leone to work with development specialist Daniel Sarmu to try and locate the species in the wild. With support of NGO Welthungerhilfe and the Sierra Leone Forestry Department, they found a single plant in one area, then located a healthy population.
Endemic to Guinea, Sierra Leone and Ivory Coast, stenophylla grows wild in hot-tropical areas at low elevation, only 400 m above sea level. They found that stenophylla grows and crops under similar climatic conditions to Robusta, but with a higher mean annual temperature requirement of 24.9⁰C (1.9⁰C higher than that of Robusta) and a substantial 6.2-6.8 ⁰C higher than Arabica. Stenophylla coffee is also reported to be drought tolerant, although this attribute requires further research.
There had been no recorded sensory information for stenophylla for 100 years, due to its scarcity in cultivation. Obtaining a small sample from partners in Sierra Leone, it was assessed by an expert tasting panel at Union Hand-Roasted Coffee in London in the summer of 2020. The panel awarded the coffee a speciality score of 80.25, based on the protocol of the Specialty Coffee Association, and identified arabica-like qualities. To reach "speciality" status, a coffee needs a score of 80 points or higher.
After this initial tasting in London, an additional and much more substantial sample of stenophylla, this time from Ivory Coast was obtained from the Coffea Biological Resources Center on Reunion Island in the Indian Ocean. The sample was evaluated at CIRAD’s sensorial analysis laboratory in Montpellier by a panel of judges, and then soon afterwards by coffee experts from companies including JDE, Nespresso, and Belco. The 15-strong panel blind tested two arabica samples (one high quality and one low grade), one high-quality robusta sample, and the Ivory Coast stenophylla.
The evaluation revealed that stenophylla has a complex flavor profile, with judges noting its natural sweetness, medium-high acidity, fruitiness, and good body. When asked if the stenophylla sample was an arabica, 81% of the judges said yes (compared to 98% and 44% for the two arabica samples, and 7% for the robusta sample).
Delphine Mieulet, scientist at CIRAD, who led the tasting, said, “The sensory analysis of stenophylla reveals a complex and unusual flavor profile that the judges unanimously found worthy of interest. As a breeder, this new species makes me hopeful about the future for quality coffee, despite climate change.”
David Behrends, managing partner and head of trading at Sucafina said, “These findings open the way for farming high-quality coffee in warmer climates, and could be part of the solution for ensuring a climate resilient coffee sector.”