Coffee Varieties, Processing, and Origin Knowledge
What you must know
Species: Arabica is higher in sucrose and lipids, lower in caffeine and chlorogenic acid, and dominates specialty. Robusta is higher in caffeine and chlorogenic acid, lower in sugar, and tastes harsher and more rubbery.
Varieties: Typica and Bourbon are the classic foundations. Gesha (Geisha) is celebrated for jasmine, bergamot, and floral intensity, notably in Panama. SL28 and SL34 deliver Kenyan blackcurrant and high acidity. Pacamara is a large-beaned Maragogype × Pacas cross from El Salvador; Maragogype is a large-beaned Typica mutant. Caturra, Catuai, and Pacas are compact, high-yield Central and South American types; Castillo and Ruiru 11 are leaf-rust resistant.
Processing: washed produces clean, bright, structured cups; natural (dry) produces fruit, wine, and body; honey sits between the two, graded white to black by retained mucilage; wet-hulled (giling basah) gives Sumatra its herbal, earthy, low-acid profile and blue-green beans; anaerobic and carbonic maceration push intense fermented fruit; monsooned Malabar is deliberately weathered.
Origins: Brazil - nutty, chocolatey, low acidity; Ethiopia - floral, citrus, tea-like; Kenya - blackcurrant, savoury, high acidity; Colombia - balanced caramel and red fruit; Guatemala - chocolate and spice; Sumatra - earthy and herbal.
Traps
- Assuming Kenya AA means top quality. It is a screen-size grade, not a cup grade.
- Treating Geisha and Gesha as different varieties. They are the same.
- Confusing honey process levels; more mucilage retained means darker honey and heavier fruit.
- Conflating natural and washed flavour signatures when the roast is dark.
Rule of thumb
Ask what the process is doing chemically: fermentation (fruit, acid) versus washing (clarity, structure).