Heap fermentation
Beans piled on the ground under leaves. The traditional West African method, workable at smallholder scale with no equipment at all.
Heap fermentation piles the wet beans on a bed of banana or plantain leaves, covers them with more leaves, and leaves them to ferment, turning the heap periodically by moving it to a fresh spot. It is the dominant method across West Africa.
Its advantages are entirely practical: no capital cost, no fixed infrastructure, and it works at whatever scale a farmer happens to have picked. That matters enormously in a sector built on plots of a few hectares.
The cost is control. A heap has an outside and an inside, and they do not ferment identically — the outer beans are cooler and better aerated, the core hotter and more anaerobic. Turning evens it out, and how well depends on the person doing it. Heap-fermented cacao is consequently more variable within a batch than box-fermented cacao, which is one reason West African quality management has historically been organised around central buying and grading rather than around the fermentation itself.
What it does
Ferments the beans in a covered pile, relying on the mass of the heap to retain heat and on periodic turning to introduce oxygen.
Why it matters
It is how most of the world's cacao is fermented, and its variability within a batch is a real constraint on how consistent the resulting chocolate can be.
- Typical duration
- 4–7 days, commonly 6
- Why the range is wide
- Heap size affects duration: a larger heap retains more heat and ferments faster at the core. There is no single correct duration, and experienced farmers judge by smell and by the colour of a cut bean.
- Optional?
- One of two main approaches. Neither is inherently better.
What it does to the flavour
Produces the same chemistry as box fermentation, with more variation between beans in a single batch.
When it goes wrong
Uneven fermentation across the heap, giving a mix of under- and properly fermented beans in one lot. Too small a heap loses heat and may not reach fermentation temperature at all.
Related
Flavour developed here
- FruityProduces the same chemistry as box fermentation, with more variation between beans in a single batch.
Commonly confused with
- Box fermentationTreated as interchangeable methods when they differ in control: a heap ferments unevenly between its outside and its core, and a box does not.
Compared in
- Heap vs box fermentationSet against Box, which readers frequently believe is the same thing.
Sources
- ChocolateHQ editorial synthesis — ChocolateHQ(citation identity confirmed; passage not re-read)
- Chocolate Science and Technology — Wiley-Blackwell(citation identity confirmed; passage not re-read)