Dark and chocolatey is what most people recognise as the flavour of coffee for one reason: that’s what Brazilian coffee tastes like. Because most coffee you’ll drink is Brazilian. But Ethiopia (birthplace of coffee) produces beans that are fruity, light and tea-like. It’s very variable, and it’s mainly down to the soil, altitude, climate, and weather events.
Arabica and robusta are just two of over 100 coffee species - the most popular ones, as it happens. Robusta is more... well, robust - high in caffeine, it’s more resistant to crop disease and insect damage. It’s also easier, and faster, to grow. That’s where the benefits end. Arabica is tastier, and will sell for much much higher prices - and it’s the only species we buy.
It’s sort of similar to tomatoes. Cherry tomatoes are very different to a salad tomato. So coffee variety affects flavour too! In Colombia, Castillo is one of the most-grown varieties. That’s because it’s disease resistant and high yielding. Whereas, in Rwanda it’s Bourbon - because it produces a high quality coffee and disease is less of a concern.