When to Pick
Coffee does not ripen all at once. On a single branch, you will find green, yellow, orange, and deep red cherries side by side. This is what makes coffee harvest fundamentally different from crops like wheat or corn -- it cannot be mechanized without sacrificing quality.
At our farms in Caicedonia, Valle del Cauca, we harvest selectively. Pickers pass through the same rows every 10-15 days during the harvest season, taking only the cherries that have reached full maturity. This is slower and more expensive than strip-picking, but it is the only way to produce coffee that scores above 84 on the SCA scale.
Reading Cherry Ripeness
Ripeness assessment is both a science and a skill. Our team evaluates cherries on:
- Color -- fully ripe cherries are deep red (or yellow for Yellow Bourbon). Under-ripe cherries are green or pale. Over-ripe cherries turn dark purple or black.
- Firmness -- a ripe cherry yields slightly when squeezed, releasing sweet mucilage. An unripe cherry is hard; an over-ripe cherry is soft and fermented.
- Sugar content (Brix) -- measured with a refractometer. Ripe coffee cherries typically read 18-24 Brix. Higher sugar means more complex fermentation and better cup sweetness.
- Taste -- yes, we taste raw cherries in the field. A ripe cherry tastes sweet and fruity. An unripe one tastes green and astringent.
The Conversion Factor
One of the most important quality indicators we track is the conversion factor -- the kilograms of cherry needed to produce one arroba (12.5 kg) of parchment coffee. At Particular Coffee, we track this weekly through 18 conversion reports across our operations.
- Below 55 -- excellent cherry quality (less waste)
- 55-65 -- good, standard performance
- 65-80 -- acceptable but indicating some under-ripe or damaged cherry
- Above 80 -- poor quality cherry that needs investigation
A low conversion factor means the pickers are selecting well and the cherries are at peak ripeness.
What Bad Picking Costs You
When unripe cherries enter the processing stream, they create defects that no amount of roasting can fix:
- Green/immature beans cause grassy, astringent flavors
- Over-ripe beans introduce fermented, vinegary off-notes
- Broca-damaged beans (from the coffee berry borer) create dirty, musty cups
- Inconsistent ripeness reduces uniformity scores in SCA cupping
Across our 1,300+ cupping samples, the pattern is unmistakable: lots harvested with strict ripeness selection consistently outscore those where picking discipline slipped.
The Human Element
Selective picking depends entirely on the skill and motivation of the harvest team. We employ experienced pickers who understand that quality starts in their hands. They are trained to leave unripe cherries on the branch and return for them on the next pass -- a discipline that requires trust and fair compensation.
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This post is adapted from Module 4 of our Seed to Cup course. Want to see real conversion factor data from our 6 farms? Join the free community at [skool.com/particular-3064](https://skool.com/particular-3064) where we share weekly harvest metrics and cupping results.
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