This article originally published in Greater Sturbridge Town & Country Living, December 2020 By Elvis Dyer, Owner/Roaster, Sturbridge Coffee Roasters
There are over 100 coffee species, however the two main ones that are widely produced and sold are: Coffea Arabica and Coffea Canephora (also known as Coffea Robusta). Arabica and Robusta differ in growing conditions, taste, caffeine content and price.
Arabica beans tend to have a sweeter, softer taste, with flavors of sugar, fruit and berries. Their acidity is higher, with that winey taste that characterizes coffee with excellent acidity. Robusta has a stronger, harsher taste, with a grain-like overtone and peanut aftertaste. Arabica contains almost 60% more lipids and almost twice the concentration of sugar than Robusta. This factor also probably has a big impact on why we prefer the taste of Arabica. Robusta beans are generally considered to be of inferior quality compared to Arabica, with some exceptions.
Arabica coffee is the more expensive of the two varietals, possessing more nuanced and delicate flavors, but also more demanding requirements for successful farming. Since it has more favorable characteristics and greater growing costs, Arabica coffee is more expensive to produce. Robusta coffee is the harsher and less expensive alternative. Robusta coffee does not have the same farming requirements of Arabica, and can survive at lower altitudes, in hotter climates, and generally resists pests more effectively. Its name is also a more accurate descriptor of its flavor characteristics as well, being more earthy, woody and a bit more bitter.
Most supermarket coffee is Robusta, and instant and less expensive ground coffees are certainly Robusta. You can still find Arabica in the grocery store, but just because it’s labeled Arabica does not mean it’s of high quality.
Arabica and Robusta coffee have different caffeine content to one another. Generally, Robusta coffee has about twice as much caffeine as Arabica. Often Robusta has its taste described as burnt tires or rubbery. One reason that the taste isn’t as good for Robusta is that it has more caffeine compared to Arabica. Which may sound like a positive thing but caffeine carries a bitter taste which makes it an unpleasant drink. The Robusta bean has 2.7% caffeine content, almost double the 1.5% of Arabica.
Arabica coffee requires partial shade in order to be grown successfully and these plants cannot withstand direct sunlight. Often, Arabica coffee is grown in conjunction with other fruits and plants to shield it from the sun. It is also more prone to pests and diseases, and it needs to be grown at higher altitudes. Robusta beans are easier to grow. They can grow at lower altitudes than Arabica beans, and they are less vulnerable to pests and weather conditions.
Robusta’s extra caffeine is a chemical defense for the coffee seed as the quantity is toxic to bugs. Chlorogenic acid (CGA) content is a significant antioxidant and an insect deterrent. Robusta is 7-10% CGA and Arabica has 5.5-8% CGA. In terms of physical appearance, Robusta beans are much more circular, whereas Arabica are more oval. Arabica plants usually grow between 2.5 – 4.5 meters compared to the 4.5 – 6 meter height of Robusta. Robusta produce fruit much more quickly than the Arabicas, which need several years to come to maturity, and they yield more crop per tree.
About 65-75% of the world’s coffee production is Arabica, about 25-35% being Robusta. Brazil is the most significant Arabica producer and Vietnam produces the most Robusta. Robusta is grown exclusively in the Eastern Hemisphere, primarily in Africa and Indonesia. Arabica is also grown in Africa and Papua New Guinea, but it’s grown dominantly in Latin America. Colombia only produces Arabica beans. Some countries, like Brazil and India, produce both.
Ultimately, it’s a question of personal taste. Despite the association with Arabica of being higher quality, and Robusta as being lower quality, that is not always 100%. Top notch specialty Robusta coffee will usually taste as good as or better than low end Arabica. However, high end Robusta isn’t widely used or available as Robusta is usually used as a filler or cost reducer.