Robusta is characterised, right from its name, by a higher dose of caffeine: almost twice as much as Arabica.
Those who choose it prefer it for its more intense and slightly more bitter taste. Robusta coffees are more 'angular', astringent, less fragrant and more bitter, with a brown to grey cream.
Its name also refers to the plant's resistance to hot weather and pests, which in the 19th century, for example, decimated hectares of Arabica crops, forcing local populations to cultivate other species.
Widespread in the tropical lowlands, it grows at altitudes ranging from 200 to 600 metres.
Similar to the Arabica plant, it has branches that bend downwards like an umbrella and blooms continuously throughout the year.
Robusta also grows on the plains. Discovered in the Congo, it was immediately appreciated for its abundant production compared to the lower cost of planting and its resistance to disease and less than optimal conditions.
The Robusta bean is more rounded, with a very straight groove, pale green in colour with grey tones: the caffeine content varies from 1.6% to 3.2%.
The roast releases much more aroma than Arabica. Some varieties, made from crosses of Robusta, are widespread in India, West Africa, Uganda and Indonesia.
There is also Arabusta, a cross between the two varieties Arabica and Robusta.