While chocolate is one of popular foods known by nearly everyone, not many are aware that the biggest contributor to its flavor is the process of fermentation. The well-loved chocolatey taste is actually the workings of microbes as they transform the raw chocolate ingredient before they are packaged and sold as delicious, melt-in-your-mouth treats.
First off, chocolates start as football-shaped seeds of growing Theobroma cacao trees. Once the seeds are scooped out of their pods, they become the beans that will be cured and drained for about three to ten days before they are sun-dried.
It is during the curing stage that fermentation happens. This stage actually produces hundreds of separate compounds as results of the fermentation process. The controlled activities of microbes make the bitter cacao seeds develop the chocolate flavor.
How Microorganisms Work During Cacao Fermentation
Cacao fermentation is a multi-step process that counts on the natural microbes present in the environment where the tree is grown. Any compound of microorganisms present in the seed contribute to the changes that will influence how the bean, and subsequently, the final chocolate product will taste.
The first part of the fermentation process involves the presence of yeast, as it creates alcohol by dissolving the sugary pulp attached in the beans. This is when molecules with a fruit-like taste called esters and the floral-tasting fuel alcohols are produced. The aforementioned compounds will then soak the beans.
Oxygen will rise from the fermenting heap while the pulp turns into pieces. This will cause a decline in the yeast population, and the oxygen-loving bacteria will convert the alcohol into acetic acid. This time, the beans will become soaked in ascetic acid that will lead to more biochemical changes.
The acetic acid bacteria actually plays a significant role on the creation of flavor as it encourages the purple polyphenol molecules to degrade into brown-colored chemicals called o-quinones. This is the part where the cacao beans’ flavor turns from bitter to nutty and rich, with the colors transforming from reddish-purple to brown. Once the sugars are all used up and the acid already evaporated, other species of bacteria, the filamentous fungi increases.
However, some microbes can destroy the fermentation if they repopulate too much as too much Bacillus bacteria can result in rancid, cheesy flavors.