Harvest, fermentation and drying
Everything that makes cocoa taste like chocolate happens in the two weeks after the pod comes off the tree, on the farm, with no equipment more complicated than a heap of leaves. It is the least industrial stage of the chain and the one that decides quality.
Harvest
Ripe pods change colour — green to yellow, red to orange — and sound hollow when tapped. They are cut from the trunk with a cutlass or a hooked knife on a pole, never pulled, because the flower cushion they grow from produces next year's pods. Harvesting runs every two to four weeks through the season; pods left too long are attacked by rodents, squirrels and black pod.
Pods are gathered into heaps and opened within a few days, usually with a wooden club or the back of a cutlass — a blade that nicks the beans lets mould in. Each pod holds thirty to forty-five beans in a white, sweet pulp. The pulp is what ferments.
Fermentation
In Ghana and Côte d'Ivoire the wet beans are heaped on banana leaves, covered, and left for five to seven days, turned once or twice. Latin American and Asian farms more often use wooden boxes. Yeasts consume the pulp sugars and produce alcohol; bacteria convert the alcohol to acetic acid; the heat and acid kill the bean's germ and start the reactions that develop flavour precursors. Under-fermented beans are slaty and bitter; over-fermented beans are hammy and putrid. The cut test used in grading is a direct check on how well this stage went.
Ghana's premium in the world market rests substantially on the consistency of its fermentation, which COCOBOD's Quality Control Company enforces at every depot. It is not a small thing: it is the reason Ghanaian beans sell at a differential and the reason a bag that has crossed the border from Côte d'Ivoire is worth more once it is called Ghanaian.
Drying
Fermented beans go straight onto raised mats or platforms in the sun for one to two weeks, raked several times a day and covered at night and in rain. The target is a moisture content of 7.5% or below; above about 8% mould develops in the bag and in the hold of the ship. In the harmattan season drying is fast and easy. In a wet main crop it is the bottleneck, and beans dried over wood fires pick up the smoky taint that buyers reject.
Well-dried beans are brittle, rattle in the hand and smell of vinegar and chocolate. They are bagged in jute and carried to the purchasing clerk, which is where the market first sees them.
Why this matters to a trader
Two things. First, weather in the drying window is as important to quality as weather in the flowering window is to quantity, and quality decides whether a crop is sold at a premium or a discount. Second, the two-week gap between harvest and delivery means arrivals lag the actual harvest, and a sudden jump in arrivals can reflect a dry week rather than a bigger crop.