Rediscovered Coffee Species Boosts Crop’s Climate Resilience Without Sacrificing Taste

The rare, wild species was well-received by taste-testers and can grow in much higher temperatures than the most commonly cultivated varieties

Coffea stenophylla
The newly rediscovered species, Coffea stenophylla, has black fruit or cherries surrounding its "beans" which are actually seeds. Plant researchers are excited by the species' tolerance of higher temperatures and desirable flavor characteristics. IRD-CIRAD

A wild species of coffee rediscovered by scientists in the forests of Sierra Leone may help the crop cope with climate change, reports Will Dunham for Reuters.

Numerous studies have predicted that as climate change raises temperatures around the globe, regions renowned for their flavorful coffees may find themselves producing bland beans or seeing diminished yields. Some studies suggest that by the year 2050, around half the land currently used for coffee growing will no longer be fit for cultivation, reports Helen Briggs for BBC News.

These risks are especially pronounced for the world’s most widely grown coffee species, Coffea arabica, because the plant prefers mild average annual temperatures of around 66 degrees Fahrenheit. The world’s second most widely cultivated coffee, Coffea canephora or Robusta, can tolerate more heat than Arabica, but Robusta is widely considered to have less desirable flavor characteristics.

Heat tolerance and flavor are what make this newly rediscovered coffee species, named Coffea stenophylla, special. It’s capable of growing in average yearly temperatures of around 77 degrees Fahrenheit, 11 to 12 degrees higher than Arabica, and, crucially, it’s much tastier than Robusta, the researchers report in a paper published this week in the journal Nature Plants. C. stenophylla’s temperature range actually extends 3.42 degrees Fahrenheit above the hardy, higher-caffeine Robusta.

"Being somebody who's tasted a lot of wild coffees they're not great, they don't taste like Arabica so our expectations were pretty low," Aaron Davis, head of coffee research at Royal Botanical Gardens Kew in the United Kingdom and lead author of the paper, tells BBC News. “We were completely blown away by the fact that this coffee tasted amazing.”

Still speaking with BBC News, Davis adds that finding a wild coffee with excellent flavor that is also heat and drought tolerant is “the holy grail of coffee breeding.”

C. stenophylla fell out of favor with farmers in the 1920s due to fears that it wasn’t productive enough and the species was thought to have gone extinct in many of the places it once grew. Per Reuters, the species hadn’t been seen in the wild in Sierra Leone since 1954 and the last wild sighting globally was in the 1980s in Ivory Coast.

But in 2018, researchers located two small, wild populations in thick tropical forests in Sierra Leone, reports Ibrahim Sawal for New Scientist.

According to Reuters, the fruit or cherry of C. stenophylla, which contains the “bean,” actually a seed, used to brew coffee, is black like a ripened olive, in stark contrast to the cherries of Arabica and Robusta which tend to range from yellow to red.

To assess the species’ flavor, the researchers recruited a panel of professional coffee judges to put C. stenophylla through its paces alongside high-quality Arabica and Robusta beans.

In the test, the judges scored the coffees on a 100-point scale developed by the Specialty Coffee Association (SCA) and guessed which species was behind a given brew. Surprisingly, 81 percent of the judges mistook C. stenophylla for Arabica, per New Scientist. The new coffee species on the block also scored a respectable 80.25 (very good) on the SCA scale.

The judges noted the wild coffee’s natural sweetness, medium-high acidity, fruitiness and pleasant mouthfeel and included tasting notes such as peach, blackcurrant, mandarin, honey, light black tea, jasmine, spice, floral, chocolate, caramel, nuts, and elderflower syrup, per a statement.

Davis tells New Scientist that C. stenophylla could be commercialized, but won’t be hitting your local cafe too soon.

“It also presents opportunities to breed with other species, like Arabica,” he tells New Scientist, potentially conferring some of its climate resilient traits to the much-fawned-over species. “It’s totally the new hipster coffee.”

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