Cacao growing, harvest and post-harvest processing
This domain tests the causal chain from farm to dried bean: how agronomy and post-harvest handling decide whether the chocolate can ever be good, and how to diagnose fermentation and drying faults.
Growing
Cacao needs 20-30 degrees C, 1,500-2,500 mm of rainfall spread through the year, and shade of roughly 30-50%, especially when young. Soils should be deep, well drained and pH 5.5-7.0. Pods are harvested every 2-4 weeks through the main crop, taking only ripe pods; ripeness shows as colour change, but the exact colour is genotype-specific, so feel and sound matter too.
Fermentation
Pods are opened within 24-48 hours of harvest, and beans with pulp go into heaps, boxes, baskets or trays for about 5-7 days for bulk cacao. The microbiology follows a sequence: yeasts convert sugars to ethanol and volatiles; lactic acid bacteria raise acidity; acetic acid bacteria oxidise ethanol to acetic acid as the mass is turned and air enters. Temperature climbs to 45-50 degrees C, the embryo dies, and heat plus acetic acid drive enzymatic browning and the formation of flavour precursors such as free amino acids and reducing sugars. Turning at roughly 48 and 96 hours equalises temperature and air and prevents edge over-fermentation.
Drying
Beans dry to 7-8% moisture over 5-10 days on mats, patios or tables. Slow, even drying prevents case-hardening; fast drying traps acids and leaves hard, sour beans.
Worked example. A heap stalls at 38 degrees C, beans stay violet after six days and taste astringent and potato-like. The fermentation never became acetic-dominant. Likely causes: mass too small, cold weather, no turning, poor drainage. Remedies: larger heap or boxes, insulation, turning at 48 hours, or a starter culture. Under-fermentation, not over-fermentation, is the more common defect.
Traps. Rigid six-day timings (bean size, pulp and climate matter); drying to 8% in a single day; storing beans above 8% moisture or near smoke; judging fermentation only by colour rather than texture, aroma and taste.