1. Morphological identification method
Bean shape comparison
Arabica: oval and flat, with an S-shaped center line.
Robusta: round and full, with a straight and deep center line.
Liberia: asymmetrical boat-shaped, with the largest volume (see gallery comparison).
Color and texture
Light roasted Arabica: light brown, with many wrinkles on the surface (silver skin remains).
Dark roasted Robusta: almost black, with obvious oily gloss.
2. Sensory practical skills
Odor diagnosis
Raw beans: Arabica with grassy/honey flavor vs. Robusta with moldy earth flavor.
Roasted beans: Arabica with fruity aroma vs. Robusta with a dominant bitter taste.
Water floating test
Steps: Take 10 beans and immerse them in a water cup. High-quality Arabica sinks faster (density ≥1.05g/cm³).