Coffee Crisis

This bean is going to save coffee from the climate crisis

One full-bodied bean is equal parts reslient and delicious.

coffee, climate crisis
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Picture this: The year is 2035.

Nations have earnestly shifted toward renewable energy sources. But it’s not enough: the climate crisis has made it much more difficult to grow crops — including the coffee beans necessary for your daily espresso. What are you pouring into your cup in this near-future world?

According to scientists, the future bean of choice might not be the current champion of the coffee world — Coffea arabica, which accounts for 60 to 80 percent of the world’s coffee production.

Instead, it’s a newcomer that has the potential to keep the coffee industry alive. It’s called Coffea stenophylla.

A close-up of the West African plant Coffea stenophylla, which scientists say could be the climate-resilient coffee bean of the future.


The hunt for a better coffee bean

Currently, Arabica dominates the global market but it is not particularly resilient to climate change. It requires certain temperatures and growing conditions that may not be as feasible due to global warming.

Other coffee beans, such as Coffea robusta — the second most popular coffee brand in the world — are considered more climate-resilient, but they lack the nuanced flavor profile of Arabica. This implies they aren’t as suitable for the high-end consumer market.

Enter the fruity, full-bodied Coffea stenophylla — also simply known as stenophylla. It’s from upper West Africa, but is more broadly known as the “highland coffee of Sierra Leone.” It’s one of 124 known coffee species.

Although it has not been commercially cultivated since the 1920s, interest in the bean reignited in 2018 following the discovery of wild populations of the plant in Sierra Leone.

The researchers obtained a wild seed sample of the plant in 2020, which they used to conduct their study.

What’s new — In a study published Monday in the journal Nature Plants, scientists argue stenophylla is a bean resilient enough to take on the climate crisis while also providing a tasty cup of coffee for high-end consumers.

This study shows it can be successfully farmed under a range of “key climatic conditions” — and that it’s delicious. In the paper, 81 percent of judges reported it resembles high-quality Arabica in taste.

“We confirm historical reports of a superior flavor and uniquely, and remarkably, reveal a sensory profile analogous to high-quality Arabica coffee,” the study team writes.

How they did it — Four panels consisting of 15 judges conducted a blind taste test of stenophylla. They used other coffee beans, such as Arabica and Coffea robusta, as points of comparison.

The judges were asked various questions, including whether the bean tasted like Arabica, whether it was commercially viable, and other questions about the bean’s flavor profile.

In a fifth panel using a different scoring system, the judges were also asked about the bean’s resemblance to Arabica.

A figure from the study showing where various coffee beans are grown in Africa, including the dominant Arabica and the newcomer Stenophylla.

What’s the flavor profile? — The judges gave a “high overall quality score to stenophylla,” confirming its shared taste profile with Arabica.

It was also found to have a similar, and in some cases, slightly higher, caffeine content to Arabica.

The bean so strongly resembled Arabica that only 47 percent of judges identified Coffea stenophylla as a different bean.

Here are a few key traits that the judges praised:

  • Natural sweetness
  • Fruitiness
  • Good body (similar to the mouthfeel of a high-quality Arabica)
  • Strong fragrance

According to the study, the scientists were pretty surprised by their findings, especially because the bean is not genetically related to Arabica.

A figure from the study showing the flavor profile of different coffee beans, including Arabica and stenophylla. Qualities such as fruitiness and acidity are associated with higher quality, while bitterness is seen as a negative trait.

The climate resilience factor — The scientists relied on existing recorded data and their own climate models to prove the bean’s resilience to rising global temperatures and increasing droughts.

They used two factors to make their case: the average annual temperatures and rainfall where the bean grows, compared to Arabica and other coffee competitors.

The scientist's climate model found that the average temperature growth for stenophylla is 24.9 °C (76.8 °F) and the average annual rainfall is 2,288 millimeters (90 inches) per year.

By comparison, Arabica has an average growth temperature of 19.0 °C (66.2°F). Although stenophylla requires more average rainfall than Arabica, its ability to withstand higher temperatures makes it an ideal coffee bean for the era of climate change.

The scientists also suggest stenophylla contains more drought-resistant properties than currently understood, though further research is required.

Why this finding matters — The coffee industry has already faced criticism for its unsustainable practices, which kill wildlife and pollute.

However, the greatest threat to the coffee industry may be its own inability to withstand harsh growing conditions posed by climate change. Recent research finds that global warming could reduce coffee-growing areas in Latin America by 88 percent by 2050.

Stenophylla has the potential to shake up the coffee industry, showing it is possible to grow high-quality, specialty coffee in a wider range of growing conditions and hotter temperatures.

The scientists write: “In the longer term, this species could have critical utility in coffee plant breeding, especially for climate resiliency.”

A photo of Arabica coffee beans. Although Arabica is the dominant global coffee bean, it is not resilient to climate change, scientists say.


What’s next — The next likely step for turning stenophylla from a wild plant into a commercially viable crop would be to create an interspecies hybrid between this newcomer and another dominant coffee bean such as Arabica.

“To ensure a commercially acceptable taste, the production of interspecies hybrids has so far relied on backcrossing with Arabica,” the team writes.

However, we still have relatively little data on stenophylla — and there is a risk of the plant dying out before we can turn it into a drinkable product. The study team argues “efforts are now required to safeguard the future of the species in the wild.”

The future of your coffee cup may just depend on these efforts.

Abstract: There are numerous factors to consider when developing climate-resilient coffee crops, including the ability to tolerate altered climatic conditions, meet agronomic and value chain criteria, and satisfy consumer preferences for flavor (aroma and taste). We evaluated the sensory characteristics and key environmental requirements for the enigmatic narrow-leaved coffee (Coffea stenophylla), a wild species from Upper West Africa. We confirm historical reports of a superior flavour and uniquely, and remarkably, reveal a sensory profile analogous to high-quality Arabica coffee. We demonstrate that this species grows and crops under the same range of key climatic conditions as (sensorially inferior) robusta and Liberica coffee and at a mean annual temperature 6.2–6.8 °C higher than Arabica coffee, even under equivalent rainfall conditions. This species substantially broadens the climate envelope for high-quality coffee and could provide an important resource for the development of climate-resilient coffee crop plants
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