A rare species of coffee has been found to have a similar flavour to the varieties favoured by coffee growers for their high quality – but it is also more tolerant of the higher temperatures and more varied rainfall that are becoming increasingly typical of coffee-growing regions.

Many types of coffees favoured for their taste only grow in a narrow range of conditions, meaning they might not survive if temperatures increase. In fact, around 60 per cent of wild coffee species are facing extinction.

Coffea stenophylla may offer a solution. Farmers stopped cultivating it in the 1920s, believing it couldn’t compete in the market at the time, and it was thought to have gone extinct in some countries where it once grew, including Guinea and Sierra Leone. But two small, wild populations were rediscovered in Sierra Leone in 2018.

Historical records showed that it had an excellent flavour, but Aaron Davis at the Royal Botanic Gardens, Kew in London and his team wanted to test this properly. Working alongside their colleagues at CIRAD, a French agricultural research centre, they created samples of coffee brewed with C. stenophylla beans and served them to five professional judging panels alongside samples of high-quality Arabica coffee (Coffea arabica) and robusta (Coffeacanephora), which is commonly used for instant coffee.

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The judges said coffee made from C. stenophylla had a complex flavour with sweetness and a good body, similar to the taste of Arabica. Some 81 per cent of judges thought C. stenophylla coffee was actually Arabica. They also gave it a score of 80.25 on the Speciality Coffee Association’s 100-point Coffee Review scale, meaning it is considered a speciality coffee.

“I was really blown away by the taste,” says Davis. “It’s rare to find something that tastes as [good] as high-quality Arabica, so this is really exciting.”

Although they aren’t that closely related genetically, C. stenophylla has chemicals in common with Arabica, like trigonelline and sucrose, which makes them taste similar. It also contains considerable amounts of kahweol, a substance known for its anti-inflammatory properties.

The team’s models, which are based on what is already known about C. stenophylla, suggest it could tolerate an average annual temperature of around 25 ºC, which the researchers say is roughly 6 ºC higher than Arabica. It is also more resistant to varying rainfall, suggesting that C. stenophylla can be cultivated in conditions where Arabica can’t.

Davis says C. stenophylla does have the potential to be commercialised, but would start in the upper price range.

“It also presents opportunities to breed with other species, like Arabica,” he says, making them more climate resilient and securing high-quality, high-value coffees for the future. “It’s totally the new hipster coffee.”

Journal reference: Nature Plants, DOI: 10.1038/s41477-021-00891-4