Excelsa Coffee: A Low-Caffeine, Climate-Resilient Species

For over a century, the global coffee trade has relied on just two species. But as climate pressure intensifies and arabica faces growing instability, attention is turning to a once-overlooked alternative: Excelsa.

Could this low-caffeine, climate-resilient species help shape the future of coffee?

Arabica Under Pressure

Today, almost all commercially traded coffee comes from two species: Coffea arabica (around 55% of global production) and Coffea canephora (robusta, around 45%).

Arabica remains the benchmark for specialty coffee. But it is also climatically fragile.

Arabica performs best at a mean annual temperature of around 24°C. When temperatures stray more than ±6°C from this range, growth is depressed. It has what researchers describe as climatic inflexibility and is highly susceptible to pests and diseases. It is also very vulnerable to frost events.

In 2025, arabica reached record prices. Rising demand combined with stock shortfalls - largely driven by climate events - pushed the market to new highs. This volatility is not a one-off anomaly; it reflects structural vulnerability.

Climate modelling paints a stark picture. Some projections suggest a 40–90% loss of suitable arabica growing area by 2080. Habitat degradation and forest clearance compound the issue.

Optimum cultivation conditions are likely to become increasingly difficult to achieve in many existing coffee-growing regions. The result may be reduced productivity, intensified farm management (such as increased irrigation), and in some cases, crop failures as areas become unsuitable for arabica cultivation.

Arabica is exceptional in the cup, but increasingly exposed in the field. When climate projections are considered, arabica has been classified as endangered in the wild.

The Overlooked Diversity of Coffee

One of the most striking facts about coffee is how little of its botanical diversity we actually use.

There are over 120 known coffee species. Yet the global trade depends almost entirely on just two.

Wild coffee species occur across tropical Africa, the Indian Ocean islands, Asia and Australasia. Many possess useful traits - including broader tolerance to heat and different disease resistance profiles - that could become critical in a warming world.

Rather than relocating coffee farms to ever higher elevations, or relying solely on changes in farming practice, the development and use of different coffee species is widely considered to be one of the most effective long-term adaptation strategies. New cultivars, hybrids, and alternative species can all play a role.

Among those alternative species, one stands out: Excelsa.

Where Excelsa Fits In

Excelsa was long considered a variety of Liberica. However, recent genomic research led by Dr Aaron Davis at the Royal Botanic Gardens, Kew, has reinstated it as its own species: Coffea dewevrei.

Interest in excelsa is growing - particularly because it was previously cultivated at scale and already has a track record within commercial agriculture.

To understand excelsa, it helps to understand its close relative: Liberica.

A Brief History of Liberica - and the Rise of Excelsa

Liberica is indigenous to tropical West and Central Africa. In the late 1800s, when coffee leaf rust devastated arabica crops across Asia, Liberica was adopted as a replacement.

For a short time, it flourished.

But its success was short-lived. The fruits of Liberica are large, with thick skin and substantial pulp. This made the coffee difficult to depulp and dry, leading to moisture management issues and inconsistent quality. At the same time, robusta emerged as a high-yielding, easier-to-process alternative.

Toward the end of Liberica’s popular era, an allied species was identified: excelsa.

Excelsa was considered superior to Liberica in sensory terms. Its fruits and seeds are closer in size to arabica, making pulping and drying significantly easier. This improves processing consistency and quality potential.

Excelsa is indigenous to Uganda and South Sudan, where it occurs naturally in low-elevation forests. One of its defining characteristics is the tree’s growth habit: excelsa trees grow tall, requiring farmers to climb ladders to harvest the fruit.

In the cup, excelsa is typically described as having low to medium acidity, low bitterness, and vibrant fruitiness. Its profile sits much closer to arabica than to robusta.

And then there is the caffeine content.

Excelsa has a reported mean caffeine content of around 0.9% — notably lower than Arabica at an average of 1.5%.

A More Diverse Future

Climate change will continue to exert pressure on coffee production. That much is clear.

The uptake of excelsa represents a meaningful diversification strategy. It is not about replacing arabica entirely. It is about widening the portfolio of species that can thrive under warmer, more variable conditions.

Excelsa offers:

• Broader heat tolerance
• Indigenous adaptation to low elevations in parts of Africa
• A cup profile closer to arabica than robusta
• Naturally lower caffeine

For producers, it may offer resilience. For roasters, it offers something distinctive. For drinkers, it presents a unique flavour experience - and a naturally lower-caffeine option.

In a changing climate, the future of coffee is unlikely to rest on a single species.

Excelsa could become an important part of a more resilient, more diverse coffee landscape. And for those of us interested in both flavour and caffeine moderation, it is a species worth paying close attention to.

Interested in naturally lower caffeine coffees? Have a look at our range here - all coffees with a lab tested caffeine content of less than 1%.

References

Davis, A.P., Kiwuka, C., Faruk, A., Walubiri, M.J. & Kalema, J. (2022)
The re-emergence of Liberica coffee as a major crop plant. Nature Plants, 8, pp.1322–1328. https://doi.org/10.1038/s41477-022-01309-5

Davis, A.P., Chadburn, H., Moat, J., O’Sullivan, R., Hargreaves, S. & Lughadha, E.N. (2019)
High extinction risk for wild coffee species and implications for coffee sector sustainability. Science Advances, 5(1). https://doi.org/10.1126/sciadv.aav3473

Davis, A.P., Gole, T.W., Baena, S. and Moat, J. (2012) ‘The impact of climate change on indigenous Arabica coffee (Coffea arabica): predicting future trends and identifying priorities’, PLOS ONE, 7(11).