Cocoa beans are fermented by piling the extracted pulp-covered beans on mats or in boxes/buckets and allowing naturally occurring microbes to break down the pulp and beans.
Here's a more detailed look at the cocoa bean fermentation process:
1. Extraction and Piling:
- After cocoa pods are harvested, the beans along with their surrounding pulp are extracted.
- These beans are then piled into heaps, placed in wooden boxes, or spread on mats or trays. Sometimes, banana leaves or reeds are used to cover the beans for protection and insulation.
2. Microbial Activity:
- The pulp surrounding the beans is rich in sugars. Naturally occurring yeasts, bacteria (primarily lactic acid and acetic acid bacteria), and other microorganisms begin to break down these sugars.
3. Key Fermentation Stages:
- Anaerobic Stage (First 24-48 hours): Initially, yeasts ferment the sugars in the pulp, producing ethanol and carbon dioxide. This creates an anaerobic (oxygen-deprived) environment.
- Lactic Acid Production: Lactic acid bacteria then convert some of the sugars and citric acid into lactic acid.
- Acetic Acid Production: As the ethanol concentration rises, acetic acid bacteria become dominant, converting the ethanol into acetic acid (vinegar). Oxygen is needed for this stage, so turning or aeration of the beans is important.
- Bean Internal Changes: The acids produced during fermentation, along with heat (temperatures can reach 45-50°C), penetrate the beans and kill the germ, leading to the breakdown of cell structure and the development of chocolate precursors.
4. Turning/Aeration:
- The beans are regularly turned or mixed (every 24-72 hours) to ensure even fermentation and aeration, allowing for optimal activity of acetic acid bacteria.
5. Duration:
- The fermentation process typically lasts 5-7 days, depending on the cocoa variety, climate, and desired flavor profile.
6. Flavor Development:
- Fermentation is a critical step in developing the characteristic chocolate flavor. The biochemical changes that occur during fermentation lead to the formation of compounds that contribute to the aroma and taste of chocolate.
7. Post-Fermentation:
- After fermentation, the cocoa beans are dried, which reduces moisture content and further develops flavor.
In essence, cocoa bean fermentation relies on the natural activity of microorganisms to break down the pulp and initiate chemical changes within the bean itself, ultimately contributing to the complex flavors associated with chocolate.
