There are more than 120 species of the coffee tree, but 80% of the coffee produced each year comes from the Coffea arabica plant. The second most common coffee produced is the Coffea canephora, better known as Robusta. Robusta is, as you might have guessed, a more robust plant with a higher resistance to heat and disease. It has twice the caffeine content of Arabica; in fact this caffeine concentration acts as a natural pesticide. Coffee growers were thrilled to discover this alternative to Arabica in the late 19th century; for all its strengths though, Robusta has a downside -- its taste is harsher and more bitter.
Producers of commodity coffee -- the kind you get in supermarkets -- tend to use the cheaper, hardier Robusta in their blends, rather than its more flavourful and delicate counterpart. For this reason, mentions of Robusta have long elicited cringes from coffee purists -- but new research shows that this much-maligned coffee bean deserves more appreciation. Commodity coffee is machine-picked, which inevitably results in poor quality control. If Robusta is given the same care that Arabica is given, however, the result is a coffee that is said to have a more complex flavour profile than Arabica. A specialty Robusta, when produced well, can beat a poorly roasted commodity grade Arabica any day. More importantly, a small percentage of Robusta in a specialty roasted coffee can increase the body of the overall blend and give you the extra caffeine boost you need.