Species, Varieties and Terroir

Two species that matter

Coffea arabica accounts for about 60 % of world production and nearly all specialty coffee. It is self-pollinating, genetically narrow, grows best at 1,000–2,200 m in the tropics, and has roughly half the caffeine of robusta (about 1.2 % by mass). Its flavour range — floral, fruit, sugar, acidity — is what specialty coffee is built on.

Coffea canephora (robusta) is hardier, higher-yielding, disease-resistant, and contains 2–2.7 % caffeine. It is more bitter, heavier, and often rubbery or woody. Traditional Italian espresso blends use 10–30 % robusta for crema and punch. "Fine robusta" exists and is improving, but it remains a different drink.

Liberica and Excelsa are minor species with unusual, smoky-fruity profiles, mostly grown in Southeast Asia and West Africa.

The arabica family tree

Almost every arabica variety descends from two lineages that left Yemen in the 1700s:

• Typica — the original; elongated beans, low yield, clean and sweet. Ancestor of Blue Mountain, Kona, Maragogipe.
• Bourbon — a mutation from Réunion; rounder beans, 20–30 % higher yield, more sweetness and complexity. Ancestor of Caturra, Pacas, SL28, Mundo Novo, Catuaí.

Common varieties you'll see on bags:

Variety	Lineage	Notes
Caturra	Bourbon dwarf mutation	compact, productive; the workhorse of Latin America
Catuaí	Caturra × Mundo Novo	hardy, common in Brazil and Central America
Castillo	Caturra × Timor hybrid	rust-resistant Colombian variety; controversial but improving
SL28 / SL34	Bourbon selections (Scott Labs, Kenya)	intense blackcurrant acidity; the reason Kenyan coffee tastes like Kenyan coffee
Gesha / Geisha	Ethiopian landrace via Costa Rica to Panama	jasmine, bergamot, tea-like delicacy; record auction prices
Pacamara	Pacas × Maragogipe	huge beans, savoury-fruity, distinctive
Ethiopian heirloom	thousands of wild landraces	the genetic heartland; most bags just say "heirloom" or list JARC numbers like 74110
Timor hybrid / Catimor	arabica × robusta	disease resistance at some cost in cup quality

Altitude and density

Coffee grown higher matures more slowly in cooler temperatures. Slower maturation means more sugar development and denser, harder beans. High-grown coffee (1,600 m+) is:

• denser — it resists extraction, tolerates hot water and fine grinds, and rarely over-extracts;
• more acidic and complex — more organic acids and sugar precursors;
• graded higher — Central American grades like SHB ("strictly hard bean") and SHG literally mean "grown high".

Low-grown coffee (below ~1,200 m) is softer, milder, and easier to extract. Brazil is the important exception: much of its coffee grows at 800–1,200 m on flat plateaus, and its chocolate-nut-low-acid profile is partly a product of that.

The bean library in this app records a density score for each coffee; the recipe matcher uses it to suggest temperature and grind adjustments.

Terroir

Soil, microclimate, shade, rainfall timing, and picking discipline all show up in the cup, but they are hard to separate from processing and variety. What you can reliably taste:

• Ethiopia — floral, citrus, tea-like (washed) or blueberry and wine (natural).
• Kenya — blackcurrant, tomato, intense bright acidity.
• Colombia — balanced, caramel, red fruit; enormous range.
• Central America — chocolate, apple, clean sweetness; Costa Rica and Guatemala especially.
• Brazil — nutty, chocolate, heavy, low acidity.
• Indonesia — earthy, herbal, full-bodied.
• Panama Gesha — jasmine, bergamot, peach; delicacy over power.

Origin is a starting point for expectation, not a guarantee. A natural Colombian and a washed Colombian from the same farm can taste more different from each other than from coffees a continent apart.