Of the thousands of varietals of coffee beans, only two are produced commercially: Arabica and Robusta.
Arabica beans, named after the Arabian province, are generally preferred to Robusta beans for two primary reasons: they are more flavorful, and contain half the caffeine.
Supermarkets often carry Robusta coffee beans or a blend of Robusta and Arabica, but only “premium” coffee has 100% Arabica beans, which means that the roasting company has formulated and supervised the blend, and that no Robusta beans were used to “fill out” the contents in an effort to cut costs. Coffee shops recognize the overall superiority of Arabica coffee beans and use them almost exclusively.
Flavor Is King
The key to flavor in a cup of coffee resides in the oil content, and thus acidity level, of its beans. Coffee oils are full of acidic compounds that, especially once activated by hot water, provide coffee with a bitterness that can be either pleasing or displeasing to the tongue, depending on its strength. Just as a moderate amount of salt can rescue certain foods from blandness, a small amount of bitterness in coffee is actually desirable, as it gives the drink its famous bite. And just as too much salt will ruin a dish, too much acid will render coffee virtually undrinkable. Robusta beans, with nearly twice the acidity of Arabica, typically require a fair amount of cream and sugar before the average coffee drinker finds them palatable. For this reason, food companies will often utilize Robusta beans in the production of coffee-flavored products such as ice cream, where the intense neighboring flavors will offset the bitter taste of the coffee.
High Quality Requires Extra Care
The Arabica tree requires more care than its rival. Its cherries (unroasted beans) fall to the ground when they ripen, making it necessary to monitor them closely and time their multiple harvests accordingly to prevent spoiling. Robusta cherries, by contrast, remain on the tree after ripening. Moreover, Arabica cherries are less resistant to insects and fungus than are Robusta, and are more sensitive to heat, light and moisture levels. Similar to a rare vintage of wine whose grapes necessitate regular pruning and a precise harvesting schedule as opposed to a simple “table” wine, Arabica is considered the more “gourmet” of the two varietals. And like a great wine, the extra effort in production is a crucial element in creating a product prized for its subtlety and delicacy.