If you’ve ever looked into roasting your own coffee beans, you’ve probably heard the words “Arabica” and “Robusta” thrown about. Everyone seems to have an opinion about these two types of coffee beans that, when harvested and roasted, end up as very similar looking cups of coffee. So what’s really the difference between arabica beans and robusta beans, and does it actually affect your daily cup of joe?
The Coffee Plant
The robusta coffee bean is the second most produced coffee bean in the industry. It is a robust and hearty plant with a quick maturation time and high yield, making it a cost-effective option for home roasting. This is offset by the potential for lower quality beans. Arabica beans are more difficult to grow and have a lower yield, but their oftentimes superior taste and quality make arabica beans the most produced coffee bean in the industry, even at a higher cost.
While arabica and robusta beans both come from the coffee plant, they come from two different varieties. Robusta beans come from Coffea canephora and arabica beans come from Coffea arabica. These plants originate and grow in different parts of the world, and have unique growing conditions that shape the chemical properties and makeup of the bean as well as the taste.
The robusta coffee plant originates in Western Africa in the sub-Sahara where it continues to be cultivated today. It is also produced elsewhere in the world, primarily Vietnam and Indonesia. The robusta plant is easy to grow up to 800m above sea level, resistant against pests and disease, and able to withstand variable weather conditions including scorching heat and sun. Coffea canephora plants mature in around two years and have a comparatively high crop yield, making the robusta coffee bean a cost-effective plant to grow.
From an environmental standpoint, because the robusta coffee plant is so resilient and hardy, a practice known as mono-cropping is sometimes used, in which the robusta coffee plant is not grown on a rotational schedule with other plants, but is instead grown year after year on the same land. This is looked down up because the land used is oftentimes taken from forests or jungles. The robusta coffee plants are grown after removing natural vegetation, and the monocrop culture has been shown to deplete nutrient levels in the soil and over time, make the soil unusable. Then, a new area of land is cleared to restart the process, leaving a barren, unusable patch of land.
The arabica coffee plant, on the other hand, grows well in Latin America, though the bean originated in Africa as well. The Coffea arabica plant is much more fragile. It needs to be grown in subtropical climates at least 600m above sea level. It is susceptible to frost, high heat, low humidity, and vulnerable to pests, disease, and improper handling. The arabica plant takes 7 years to mature and start producing coffee seeds (beans) and additionally, has a lower yield than the robusta coffee plant.
With the comparative difficulty in producing the arabica bean, arabica coffee is naturally more expensive. You would expect then that robusta coffee accounts for the majority of coffee bean production and purchasing. But strange as it seems, arabica coffee makes up over 60% of the world’s coffee production.
The Coffee Bean
The most important thing about coffee is of course the taste. This depends on a variety of factors, from the acidity of the bean to the relative oil content, which depends on how the bean was grown, when it was harvested, and so on. The same issues that make arabica beans a hassle to produce–its inflexible climate needs, delicate structure–make it taste that much better to the average consumer.
Bean
Arabica coffee beans are usually picked by hand. The fruit on an arabica coffee plant do not all ripen at once, so the coffee berries need to be picked individually at peak ripeness. The bean is both lighter in color and larger than the robusta bean and comes in an oval shape. Robusta coffee plants need to be cross pollinated in order to bear fruit, unlike arabica coffee beans. The bean is smaller, rounder, and darker than arabica beans.
Taste
Coffee made with arabica beans tend to have a softer palate. They have high acidity and are on the sweeter side, with notes of berries or coffee being reported. Coffee made with robusta beans, on the other hand, are harsher and often described as “earthy”. Robusta beans are less acidic and have less sugar than arabica beans, and this is reflected in the coffee as sometimes bitter. That being said, a high quality robusta can add depth of flavor and is in fact highly valued in Italy specifically for how it enhances an espresso.
Composition
Robusta beans have a low sugar content of around 3%. They also have a relatively high caffeine content, over 2%, and a high cholorogenic acid. Together, the high caffeine and cholorogenic acid content leads to the bitter taste found in robusta beans. The arabica bean, on the other hand, generally has a sugar content of 5%-9% and a high oil content. It also has lower caffeine (about half that of robusta beans) and cholorogenic acid content, which leads to its sweeter, smoother taste and decreased bitterness.
Choose robusta beans if:
- you want a bitter and harsher coffee taste, or an espresso with depth
- you want coffee less acidic, less sweet
- you want more caffeine per cup
- you don’t mind potentially having to source for high-quality beans
- cost is a priority
Choose arabica beans if:
- you want something floral, sweet, or highly acidic
- you don’t mind less caffeine in your coffee
- you don’t mind paying a bit more money
Or Choose Both:
There are many commercial brands now offering arabica/robusta blends, a compromise between the high acidity and low caffeine found in arabica beans and the harshness and bitterness found in robusta beans. A blended coffee can balance out two very different tasting coffee beans, mellowing out arabica beans and brightening up robusta beans. Or try a 70/30 variety. The great thing about roasting your own coffee is you’re in control.