- The shape of the bean: arabica bean is oval with a sinuous groove; robusta bean is more circular with a straight groove; arabica is also lighter in color than robusta;
- The chromosomes: arabica has 44 chromosomes, robusta has 22;
- Pollination: arabica plant is a self-pollinating plant that means that there will be less mutations and variations because it will not be affected by a combination of genetic factors; robusta plant, on the other hand need to be pollinated, so there will be more mutations and variations caused by the majority of the case by insects and environmental factors like wind and water;
- Caffeine: robusta bean has basically double the amount of the caffeine instead of arabica one; 2,7% compared to 1.5% of arabica;
- The taste: arabica is sweetener than robusta cause of different factors such as lipid and sugar content, caffeine, chlorogenic acid, growing conditions, etc, etc.
Lipids and sugars content are responsible for the aromatic compounds during the roasting. Arabica beans contains twice the amount of sugars and has roughly 60% more of lipids instead of robusta beans. That’s why arabica has the finest quality.
Caffeine and chlorogenic acids are high in level in robusta beans, so that’s the reason why we taste bitterness when we drink a cup of coffee (we are drinking robusta or unfortunately whatever that is over-extracted).
The plants of arabica need higher altitude (600-2000m), a rich soil and abundant rain; the robusta ones can be cultivated in the lowland areas (0-600m) cause it’s stronger so it doesn’t suffer from hot temperature. Robusta plants is also higher in yield than arabica ones.
- The Price: robusta bean is costs roughly half the price of arabica mainly because it costs less investment for the farmers and produce lower quality. Robusta beans don’t need to be tend by the farmers as much as arabica beans need.
- Resistant to disease and climate: robusta is really resistant to parasites and climatic conditions; arabica is extremely delicate to pests, fungal diseases and suffer from harsh changes, direct sunlight, strong wind and heavy rain.
- The market: 70% of the world production is made by arabica plants and less than 30% is made by robusta ones (liberica and excelsa are 2%).
I am an Italian coffee lover that pushed for the love of this “amazing drug” decided to come to London to study about coffee and its different extraction procedures and tastes.