What is the Robusta coffee bean species?

Robusta is a resilient, strong coffee plant, and is the second most common species in
the world. Around 25% of all coffee sold worldwide is Robusta, which is native to
West Africa but is today also grown in Brazil, India, Indonesia, Vietnam, and
Southeast Asia.

The beans are dome-like and round and are light green in color. Robusta is bitter in
taste, has a high caffeine content (2%-4.5%) and a thick crema (the layer of foam on
the surface of a shot of espresso). It is considered inferior to the Arabica species.