Arabica vs Robusta: 7 differences

Although there are approximately 120 varieties of coffee, Arabica (Coffea arabica) and Robusta (Coffea canephora) are the most commonly grown varieties. Arabica accounts for around 60% of global coffee production and Robusta accounts for around 39%. There are a number of differences that set these two popular types of coffee apart. As independent species, they each have their own characteristics. So what is the difference between Arabica and Robusta coffee?

Coffea Arabica vs Robusta (Canephora): An Overview of the Differences

characteristics	Arabica	Robusta
plant species	Coffee Arabica	Coffea Canephora
Appearance of the bean	Flat, oval with a curved S-shaped incision	rounder, smaller with a straight incision
Main growing areas	Ethiopia, East Africa, Brazil, Colombia, Caribbean	Vietnam, Indonesia, Brazil, Central and West Africa
Growing conditions	Delicate, requires special soil and climate	Resistant to diseases and different climatic conditions
ripening time	9 months	10-11 months
Climate and altitude	Constant temperatures, shade, high humidity (humid subtropical), best at 900 to 2300 m above sea level	Warm climates, 200 to 800 meters above sea level
Plant height	up to 5 meters	up to 9 meters
Harvests per plant/hectare	Lower harvest	Higher harvest
DNA	44 chromosomes	22 chromosomes
Market share	approx. 60%	Approx. 39%
Caffeine content	1.1 - 1.7%	2 - 4.5%
Chlorogenic acid content	1 - 2%	2 - 4%
sugar content	6 - 9%	3 - 7%
Flavor profile	Fruity, nutty, chocolaty, sweet and floral notes	Earthy, robust, slightly bitter
Mostly used	As a single origin in filter coffee, French press and espresso etc.	in espresso blends and instant coffees

1. Growing conditions

The Arabica coffee tree grows in subtropical climates with high humidity on shady and nutrient-rich soil. It grows to a height of 2.5 to 5 meters, grows at temperatures between 15°C and 24°C and requires an annual rainfall of 1200 to 2200 mm per year. The Robusta variety, on the other hand, grows slightly taller (4.5 to 6.5 m) and prefers slightly warmer temperatures (18 to 36 °C) and slightly more rainfall (2200 to 3000 mm per year).

Arabica coffee grows best at higher altitudes, usually between 900 and 2300 meters above sea level, and is often grown in hilly areas. Robusta, on the other hand, grows best at lower altitudes, between 200 and 800 meters above sea level. Robusta is grown in areas where Arabica is attacked by fungi and pests.

Robusta coffee is much more resilient to warmer conditions than Arabica coffee. It is assumed that the area under cultivation for Arabica will shrink due to climate change. Producing the same amount of Arabica coffee to meet global demand is no longer sustainable in the long term. Therefore, there is growing interest in Robusta coffee and in selective breeding methods to improve taste, oil content and other desirable characteristics.

aspect	Arabica coffee	Robusta coffee
Climate	Subtropical with high humidity, shade, fertile soil. Requires stable constant temperature	Slightly warmer, higher rainfall, lower altitude. More resistant to warmer conditions
Plant height	up to 5 meters	up to 9 meters
temperature	15°C to 24°C	18°C to 36°C
Rainfall	1200 to 2200 mm/year	2200 to 3000 mm/year
Height preference	900 to 2300 meters above sea level (hilly areas)	200 to 800 meters above sea level
Growing challenges	Susceptible to fungi and pests	More resistant to fungi and pests, hence the name Robusta

2. Shape of coffee bean

Arabica coffee beans are slightly larger and have an oval shape with an S-shaped incision, while Robusta beans are rounder and smaller and have a straight incision in the middle.

3. Caffeine and chlorogenic acid

The caffeine content of Robusta coffee is almost twice that of Arabica coffee: 2.7% caffeine compared to 1.45% for Arabica. Robusta coffee also has a higher content of chlorogenic acid compared to Arabica coffee.

Robusta coffee's stronger flavor and bitterness are attributed to its higher caffeine and chlorogenic acid content, which is why it is not well received by coffee lovers. However, the Robusta variety's higher caffeine and chlorogenic acid content makes it more resistant to diseases and pests - hence the name Robusta. The Robusta plant's higher caffeine concentration and higher chlorogenic acid content are believed to be due to the plant's defense mechanism against diseases and pests. The Arabica plant, on the other hand, is a delicate plant that requires special attention and care as it is susceptible to pests and diseases.

4. Lipid and sugar content

Arabica has over 60% more lipids and almost twice the sugar concentration as Robusta. The lipids and sugars contained in raw coffee beans serve as precursors to aroma and taste and significantly influence the quality of the brewed coffee. During the roasting process, these lipids and sugars play a crucial role in developing the aroma and flavor profile of the roasted coffee.

Roasters often blend Robusta beans with Arabica beans to control and balance the bitterness caused by the Robusta bean's lower sugar and lipid content and higher caffeine content.

5. Pollination

Arabica coffee plants are self-pollinating, meaning they can fertilize themselves, while Robusta coffee plants are self-sterile and rely on cross-pollination from wind, bees and other insects. Arabica with the ability to self-pollinate generally remains stable as a species because cross-pollination is less likely. Robusta, on the other hand, is self-sterile and requires cross-pollination for reproduction, making it more dependent on external factors.

This difference in pollination mechanisms has implications for the cultivation and management of these two coffee varieties, as well as their genetic diversity and their resilience to environmental changes.

Robust coffee is more genetically diverse than Arabica coffee and one of the main reasons for this is that it cannot self-pollinate. Lack of self-pollination means that different varieties are grown in the same area and mix with each other. Due to the lack of genetic uniformity, many Robusta farmers do not know which specific variety or subvariety they are growing, which can prevent them from choosing varieties with better flavor profiles that appeal to a broader range of consumers. However, the genetic diversity of Robusta allows the plants to adapt to different environmental conditions, such as climate fluctuations.

6. Number of chromosomes

Arabica coffee beans have 44 chromosomes, while Robusta coffee beans have half as many, 22 chromosomes. Robusta's genetic code is distributed across 22 chromosomes, while Arabica has twice as many. Because Arabica coffee beans have more complex DNA than Robusta beans, they have a broader flavor spectrum, a more complex flavor profile and a fragrant aroma.

7. Taste: Arabica or Robusta

It is important to know that even within a variety or type of coffee beans there are differences in quality and taste. Take Ethiopian Yirgacheffee coffee, for example. Although the bean itself is an Arabica variety, the unique environmental conditions, particularly the altitude and volcanic soil in Yirgacheffee, give these beans a unique flavor profile that sets them apart from Arabica beans grown elsewhere.

However, there are clear taste differences between Arabica and Robusta beans. Arabica beans have a softer, sweeter taste with a variety of flavor notes including fruity, floral, sweet and chocolatey notes. Traces of fruit or berries can often be found in the taste profile of high-quality Arabica coffee. Robusta beans, on the other hand, have a stronger, more robust and bitter taste with pronounced burnt undertones.

While some people enjoy the strong bitterness of Robusta coffee, Arabica coffee is generally considered to be superior in taste and aroma and is preferred as a single origin for French press coffee, espresso coffee and filter coffee. Robusta coffee was primarily used for instant coffee and as an inexpensive filler in espresso blends, where it provided more crema and caffeine.