Robusta is a Canephora coffee plant varietal (Coffea canephora var. robusta), and one of the two main commercially cultivated coffees along with Arabica (Coffea arabica) and its varietals. A relatively small about of Liberica Coffee (Coffea liberica) is also grown commercially.
While learning about the different coffee varietals can be fun and interesting, we recommend choosing your coffee based on personal taste preferences rather than arbitrary genetic distinctions.
Common Uses of Robusta Coffee Beans
Robusta coffee beans are used for most instant coffees, and contain about twice as much caffeine as Arabica Coffee beans. Many of the world's largest commercial coffee roasters use large quantities of Robusta beans.
Growing Robusta Coffee
Robusta plants are easier to grow (e.g., more “robust”) because they tolerate less favorable soil and climate conditions and grow at lower elevations.
In contrast, the Arabica species is more prone to coffee diseases, more vulnerable to pests, more sensitive to handling and temperature, and has a lower yield per plant - thus Robusta coffee is less expensive to grow.
Robusta coffee plants may reach 30 feet (10 meters) in height, yet their root system is very shallow. The roundish Robusta coffee cherry (fruits) may take up to 11 months to mature, and encase oval-shaped coffee beans that are generally smaller than Arabica beans.
Roasting Robusta - Favored for Espresso Coffee Blends
Before Robusta beans are roasted they conjure smells of peanuts or oats, giving off a nutty, grainy fragrance. Once they are roasted, Robusta beans often smell burnt (e.g., burnt rubber or plastic), and perhaps slightly woody. Robusta coffee tends to be bitter compared to Arabica. Robusta also has less pleasant acidity levels.
Though Robusta coffees have no significant presence in the coffee market, they are often used as a base in espresso blends to enhance the body of the espresso.
Robusta Coffee Growing Regions
Robusta is also grown in Brazil, where it is called Conilon.
Hybrids of Robusta and Arabica - The Sarchimor Varietal
In addition there are hybrid forms of coffee plants that cross Robusta with Arabica varietals with the goal of conferring disease resistance and “robust” plant qualities on the Arabica varietal or conferring desirable flavor and aromatic qualities on the Robusta varietal.
For example, the Sarchimor coffee plant varietal is a hybrid between the Timor varietal and the Costa Rican Villa Sarchi varietal (Coffea arabica var. villa sarchi). Due to traits inherited from the Timor varietal (which is itself a hybrid of Coffea canephora var. robusta and Coffea arabica), the Sarchimor varietal has a significant resistance to the coffee disease coffee leaf rust (Hemileia vastatrix) as well as the stem borer.
Catimor, Arabusta and Icatu Varietals
The Catimor coffee plant varietal (Coffea arabica var. catimor) is a cross between the Caturra varietal (Coffea arabica var. Caturra) and Timor. Catimor coffee plants are known for their resistance to coffee rust and produce among the highest yields of commercial coffee plants.
Icatu hybrids are created through repeated backcrossing of hybrids of Coffea arabica and Coffea canephora var. robusta with the coffee plant cultivars Caturra (Coffea arabica var. caturra) and Mundo Novo (Coffea arabica var. mundo novo).
Coffee and Espresso Brewing Tips
Also check out the history of the revered beverage in our World's Best History of Coffee.