Sourcing explainer from the Sunex Commodities trading desk.
Most industrial roasters buy both Robusta and Arabica, and the blend is where the economics and the cup meet. This note sets out how the two differ in ways that matter to a roaster sourcing at volume.
The basics
| Robusta | Arabica | |
|---|---|---|
| Species | Coffea canephora | Coffea arabica |
| Growing altitude | Lowland, sea level to ~800 m | Highland, ~900–2,000 m |
| Caffeine | Higher (~2–2.5%) | Lower (~1.2–1.5%) |
| Cup body | Full, heavy | Lighter, more acidic |
| Flavour | Earthy, woody, bitter | Floral, fruity, citric, complex |
| Price | Generally lower | Generally higher |
| Main use | Espresso blends, soluble, extraction | Single-origin, filter, premium blends |
Screen size
Coffee is graded by screen size: the diameter of the bean.
- Robusta: typically screen 14–18; larger screens (16, 17, 18) command a premium.
- Arabica: screen 14 up to 17/18, plus peaberry (single round bean).
Screen size affects roast evenness and yield. A roaster buying a blend wants consistent screen within a lot to avoid uneven roasting.
Defects and cup score
- Commercial grade trades on screen and defect count (defects per 300 g).
- Specialty grade (Arabica, 80+ cup score) trades on cupping report (flavour, acidity, body, balance) verified before contract.
Robusta is rarely cupped for specialty in the Arabica sense, but fine Robusta is an emerging category with its own cup protocols.
Processing
- Washed Arabica: clean, bright, acidic, preferred for specialty.
- Natural Arabica and Robusta: heavier, fruitier; common in Brazil and Ethiopian naturals.
- Honey / pulped-natural: sweet, balanced.
Industrial roasters often buy natural for body and washed for brightness and blend to taste.
Price and the futures market
- Robusta references the ICE Futures Europe (London) Robusta contract.
- Arabica references the ICE Futures (New York) Arabica ("C") contract.
A roaster fixing price can do so against the relevant futures curve plus a basis (the differential for origin, grade and quality). The basis is where origin, screen and cup quality show up in price.
Blending for industry
- Espresso blends: a Robusta component adds crema, body and caffeine; an Arabica component adds aroma and acidity. 10–30% Robusta is common.
- Soluble / instant: Robusta's yield and price make it the backbone of instant coffee.
- Filter and specialty: Arabica, often single-origin.
Sourcing both with one counterpart
Sunex trades both species across African and South American origins. For a roaster buying both, a single counterpart with origin presence in both Robusta (Cameroon, Uganda) and Arabica (Ethiopia, East Africa, South America) origins simplifies logistics, documentation and quality assurance.