Most of us are familiar with the term “Arabica” found on the pack of espresso sold at the supermarket. Actually this is pretty misleading, since a real espresso consist of a blend of Arabica and Robusta beans. Likewise, there’s this rumor floating around that only Arabica beans are really good coffee beans. That’s not entirely true. So what’s up with Arabica and Robusta?
Arabica is the most important type of coffee in the world. It makes up 60 percent of world trade and is grown in the highlands, in places such as Kenya, Colombia and Central America. Robusta is a fast-growing, more productive and more resilient than Arabica. It grows in areas up to 600 metres above sea level and is used as supplementary bean mainly for the preparation of espresso, because it supports the formation of “crema” and brings a heavy, slightly earthy flavor. Crema is the dense, golden brown foam that forms on properly prepared Espresso.
You need certain a proportion of high quality Robusta beans and the correct water pressure to enhance a luscious crema on a shot of espresso. The more expensive, superior Arabica coffee beans impart a slightly acidic, full taste with little bitterness and a light crema. As a result, you experience a fruity, light, mild and sweet taste from the Arabica bean.
Whereas, the Robusta coffee has less acid (since it can be roasted longer) and reveals a rather bitter, earthy taste with a hint of chocolate, somewhat comparable to bitter dark chocolate. It gives a dark crema and adds “body” to coffee. Essentially, the great (or not so great) tasting espresso we drink is solely dependent on the mixing ratio of the two types of coffee beans. A mixture of Robusta helps achieve a perfect balance of heartiness and body, to the smoothness and mildness of Arabica.
In most espresso, there is always a higher proportion of Arabica. However, the proportion of Robusta is regionally different. Many so-called “Italian bar mixes” mainly in southern Italy, use up to 50% Robusta. Toraldo of Naples use up to 30% Robusta coffee and the further north you go, the less is the proportion of Robusta. But to give up completely is generally poor for the taste. It’s the expert recognizes the really good espresso by its crema.