There are two species of coffee that dominate global production: Coffea arabica and Coffea canephora. Canephora's most widely cultivated variety is Robusta - a name so dominant that it's become common shorthand for the species itself, even though strictly speaking they're not the same thing.
Arabica accounts for the majority of specialty coffee production worldwide. It's grown at higher altitudes, is more sensitive to climate and disease, and produces beans with greater complexity, more nuanced acidity, and a wider range of flavour potential. It's also harder to grow, which is reflected in the price. Robusta, as the name suggests, is hardier. It tolerates lower altitudes, higher temperatures, and less favourable growing conditions, and it produces a higher yield per plant. The trade-off is in the cup: Robusta is higher in caffeine, heavier in body, and significantly more bitter, with less of the complexity that makes Arabica interesting. It's widely used in commercial espresso blends and instant coffee, where its body and crema-producing qualities are useful. In specialty coffee, it's rarely the star.
There is a third species - Coffea liberica - grown in small quantities in parts of West Africa and Southeast Asia, with a distinctive, sometimes polarising flavour profile described variously as floral, smoky, or woody. It's genuinely rare in specialty circles and worth knowing about, but not something you'll encounter often.
Arabica accounts for the majority of specialty coffee worldwide - and everything in our current range is Arabica. That said, the gap between Arabica and Robusta is narrowing in some corners of the specialty world. A small number of producers, particularly in Vietnam and India, are producing what's being called 'Fine Robusta' - single-origin beans with more nuanced flavour profiles than the commercial Robusta most people know. It's an emerging category worth watching.