Coffee Cherry
Sources: El Arte del Café by Sébastien Racineux & Chung-Leng Tran (Lunwerg, 2017)
Anatomy
A coffee cherry typically contains two beans (seeds) facing each other flat-side inward. Occasionally it contains one bean (peaberry / caracolí in Spanish), which is rounder. Rarely, three or more beans. (source: El Arte del Café)
From outside to inside:
| Layer | Spanish | Description |
|---|---|---|
| Skin (piel) | Piel | Outer fruit skin |
| Pulp | Pulpa | Fleshy fruit layer |
| Mucilage | Mucílago | Viscous layer adhering to the endocarp; drives fermentation in wet processing |
| Endocarp | Endocarpio | Hard protective layer (parchment) around the bean; removed in hulling |
| Silver film | Película plateada | Thin membrane directly on the bean; mostly removed in hulling |
| Bean | Haba / Grano | The seed — what becomes roasted coffee |
The endocarp protects the bean; the mucilage is the fermentable sugar layer exploited in wet processing.
Colour and Maturity
Green when unripe → red or yellow at maturity (depending on variety). Some varieties produce orange or pink cherries. Colour is the primary visual indicator for selective harvest, though it is an imperfect proxy — maturity timing varies within the same branch. (source: El Arte del Café)
Production per Plant
One coffee plant (cafeto) produces 1.4–2.5 kg of cherries per year — some varieties are more productive than others. This translates to 266–475 g of green coffee, and ultimately 204–365 g of roasted coffee. A single plant may produce less than one 250 g retail bag of roasted coffee per year. (source: El Arte del Café)
Lifecycle of the Coffee Plant
Germination: 3–4 weeks from planting to first root emergence; 3–4 weeks more for the stem to emerge; at 10–12 weeks, the endocarp detaches and first true leaves (dark green, opposite pairs) appear.
First cherries: 3–5 years after planting.
Mature plant height: 2–3 m (managed by pruning) to 3.5–6 m (Typica, Maragogype).
Flowering: Triggered by rain. Flowers last briefly; fruits take 6–9 months to mature after flowering. If first rain is irregular, cherries on the same branch will be at multiple stages of maturity simultaneously — requiring careful multi-pass selective picking.
Seed viability: Germination power declines rapidly. From 95% at <3 months, it drops to 75% at 3 months, 25% at 9 months, and zero at 15 months. Storage at 15°C in vacuum packaging can extend viability up to 6 months.
Growing Conditions
Coffea arabica grows in the tropical belt, between the Tropics of Cancer and Capricorn.
| Zone | Altitude | Rainfall pattern | Harvests per year |
|---|---|---|---|
| Subtropical | 600–1,200 m | Distinct wet/dry seasons | 1 |
| Tropical | 1,200–2,400 m | More frequent rain, near-constant flowering | Up to 2 (main + smaller) |
Shade: Most arabica varieties prefer partial shade. Farmers plant banana, papaya, and other fruit trees to recreate natural shade. This creates an agroforestry system: possible soil symbiosis between fruit trees and coffee plants may add aromatic complexity, though not yet scientifically confirmed. Prevents soil erosion; provides biodiversity habitat. See Organic Farming. (source: El Arte del Café)
Altitude and flavour: Higher altitude = slower maturation = denser beans = more complexity.
| Altitude | Cup character |
|---|---|
| 1,500–2,000 m | Floral, spiced, fruity, acid, maximum complexity |
| 1,200–1,500 m | Acidity develops, more aromas |
| 1,000–1,200 m | Scarce acidity, round |
| 800–1,000 m | Acid, low complexity |
Kaiserblick’s farms in Apaneca-Ilamatepec sit in the upper altitude bands, supporting complex, acidic, floral profiles suited to light roast filter.
Propagation
Cutting (desqueje): A branch tip with two leaves, halved, is planted. Once rooted, it grows as a genetic clone of the parent. Cloning preserves desirable traits exactly.
Seedling (brote): Fully ripe cherries are selected, depulped, briefly fermented (<10 hours), dried, and planted in nursery bags with appropriate substrate (friable, light, fertile). Seeds are germinated in controlled nursery conditions (shade, irrigation, shelter). At 40–60 cm height with 10+ leaf pairs, seedlings are transplanted to the field.
Pollination: Coffea arabica is self-pollinating (wind is primary vector); insects contribute only 5–10%.