Have you ever wondered what species of coffee you are drinking? Most people probably heard the words arabica or robusta, but there’s more than 120 unique species of coffee tree with countless varieties and cultivars. Unfortunately, only a few are commercially useful. 98% of the coffee market consists of only two species, the aforementioned coffea arabica with a 60% share of the market, and coffea canephora, colloquially known as robusta, which is an outdated synonym. This one constitutes about 40% of the production. A minority, only about 2% of the coffee market, is made up of coffea liberica and its variety, coffea liberica excelsa.
There are important differences between arabica robusta, in some ways, they are almost opposites of each other. Robusta is a truly sturdy plant. It doesn’t need nearly as delicate conditions for its growth as arabica does. It is easier to cultivate, which is possible already from the altitudes
of 800 m.a.s.l.. Its name does not come out of nowhere - it has a hardier root system, it is generally bulkier and grows faster, starts giving fruit sooner, yields more, the cherries can grow larger and contains up to double the amount of caffeine of arabica. An easy way to tell it from arabica is by its typically wrinkled leaves.
There is a longstanding belief that the taste profile
of robusta is nowhere near as rich as the one of arabica, and that’s why it has long been considered something lesser, uninteresting and has been destined for a life of commodity coffee. The taste expectations in robusta are usually focused on earthy, alkaline tastes distantly reminiscent of nuts or chocolate. But in properly cultivated and processed robusta, one might find a far richer spectrum of tastes, such as aromatic woods like cedar or sandalwood and spices such as cinnamon or clove. The defining characteristic of robusta are its exclusive alkaline flavours, for example black tea, cotton, dried tobacco or fresh tobacco leaves. Robusta can reach high sweetness levels and remind of ripe bananas, papaya or other fibrous fruits. And in special cases, the alkaline taste makes space for an acidic taste, which bring the taste of the coffee close to arabica.
Working with robusta, one might notice it is a very stable coffee boasting a thick crema, the characteristic foam topping a cup of espresso. It is these properties, such as stability, higher caffeine content, rich crema and lower price, which made robusta a traditional part of Italian espresso blends, where it complements the taste qualities of arabica. According to the original recipe, ristretto is even prepared out of 100% robusta.