Linking a certain cacao flavour to a certain origin or region, is very much a romanticized concept. Though, the truth is, there is very little scientific evidence on the impact of origin on cacao. A certain region can have specific yeasts and bacteria that can steer the natural process of fermentation of cacao, and this can have an impact on the final flavour. But if we look at soil and climate, there is very little scientific evidence of its impact on flavour.

To the contrary, there are multiple parameters that have been in fact proven to have a significant impact on flavour development, and today we will highlight the “post-harvesting” aspect.

In order to get a real flavour sensation with cacao, it is crucial to properly manage the fermentation and drying process. You can compare it to cooking! You may have the most exclusive, high-quality ingredients, but if you’ve never set foot in the kitchen, your dinner is likely to fail… While if you follow an excellent recipe, you could turn out to be a true Gordon Ramsay!

Needless to reiterate that also for cacao applies that if your ingredients aren’t fresh or taste off, the end product will be worthless as well. So let’s take a closer look at the technicalities of the cacao post-harvesting process and its impact on flavour development.

The flavour development of cacao starts with the all the important “ingredients”. Every fresh cacao fruit has a certain potential for flavour development and several flavour paths can be followed.

On the one hand, you have to look at the genetics and on the other hand at the sugar content and acidity of the pulp of the fresh fruit. A good fermentation protocol always starts with the quality of the fresh cacao and the materials you work with. When the beans are still in the fruit, they are covered with a white mucilage coating. This coating has a high sugar content (this can be checked by measuring °Brix) and is a source of nutrition for the beans when it germinates. Beans begin to germinate as soon as the fruit has been picked. The freshness and quality of the wet mass can be assessed on the basis of °Brix and can be used as a first indication of how long to ferment the cacao.

According to Zoi Papalexandratou, post-harvest expert, the development of flavour does indeed start with the initial situation in the field: “Based on field observations, I can underline the range of potential that exists for different flavour profiles. By carrying out various experiments, we will then choose one specific flavour profile and we will draw up a protocol with which we think we can achieve that specific flavour”.

Once the cacao pods are opened (ripe of course!), and the beans are removed from the pod, there is an exposure to oxygen and microbial “zoo”, and the fermentation process starts almost immediately. The fermentation process is as follows; Naturally-occurring yeasts settle on the pulp and start to split the sugar into alcohol and carbon dioxide. Thereupon bacteria start to oxidize the alcohol and processes of acetic and lactic acidification take place in aerobic and anaerobic conditions (Are you still following? 😉). During these processes, temperature rises, pH of the mass increases, and finally the embryon of the beans is killed and the cell wall breaks down. This is when complex chemical processes of enzymatic activity inside in the bean, like breakdown of sugars and proteins into amino acids take place. “During this process it is very important to follow up closely”, Zoi explains. “You can have an initial protocol in your head, but you have to follow up on the microbial changes and whether they are working in your favor. If not, it can be necessary to adjust the protocol along the way”.

Quite a complicated explanation but it’s important as this is where the real magic happens! So let’s summarize it in a few easier-to-understand steps.

1. First there is a breakdown of the pulp around the seeds
2. Thereafter the embryon in the seed is killed
3. And finally the proteins and carbohydrates are broken down into amino acids and reducing sugars.

Zoi points out that there are two crucial elements during this fermentation process. “Often people explain the fermentation process as ‘x number of days and x number of turns’. While this can certainly give a first idea, you have to look beyond this. There are two elements that are crucial and that is a practical parameter and a measurable parameter. From a practical point of view, it is important how the farmers mix the cacao during the fermentation process. The same type of cacao mixed in a different way can lead to a completely different end result. Measurably, the change in the cacao bean pH value is crucial. This will determine how long the beans have to be fermented for.”

The magic that happens during the fermentation process will ultimately ensure flavour development and allow chocolate makers to unleash their creativity and obtain amazing flavour profiles! A properly controlled fermentation will result in positive flavour developments such as fruity, floral, nutty and spicy flavours. Incorrect fermentation can result in negative flavour developments such as ammonia or rancid off-tastes.

Having good control over the fermentation process does remain a challenge for cacao. What we see in cheese and wine, for example, but also in coffee today is that “starter cultures” are often used. For cacao we still use spontaneous, natural fermentation. Possibly cacao will follow the same trend, but it has more challenges due to a more complex microbial consortium and higher production costs for starter cultures.

The fermentation process may now sound like the primary element that ensures good flavour, but the drying process is certainly just as important. “When I talk about flavour development, I usually say that 30% is dependent on genetics and 70% on post-harvesting. So it is not only the fermentation that is critical, you have to think of the fermentation and drying process as a package” Zoi explains.

During the cacao drying we want to stop the fermentation process, and reduce the humidity of the beans.  While climate is not so important during fermentation it does have a very important role during the drying process. Natural sun drying and open air drying are always preferred, but for certain origins the weather conditions do not allow this. To give an example, in Nicaragua where it is quite humid, farmers are encouraged to also use artificial drying. The intention is to let the humidity drop naturally for about 5 days and to end with an artificial drying in such a way that the artificial aspect cannot have a negative impact (for example smoky flavors, lowering too much acidity, broken shells, etc.).

Flavour expression is always the result of teamwork! It starts in the field but it ends with the chocolate makers. It’s in the chocolate makers favor to recognize that not all beans are suitable for all purposes. Chocolate makers should look at the beans’ potential, interpret it, and decide what they want to achieve. The same beans can express different flavours. What we often see is that the same beans give completely different results due to the chocolate maker’s interpretation and creativity. We thus highly encourage you to experiment with roasting and refining to express the potential of your beans. In the end, it’s a bit like swiping on Tinder until you find the beans that match you perfectly!