Fresh cacao seeds do not yet taste like chocolate
Fresh cacao seeds taste nothing like what we associate with finished chocolate. They are mainly bitter, partly nutty and can leave an astringent, slightly fuzzy mouthfeel. It is only after harvesting that the crucial processes begin which shape the cacao’s later aroma.
To do this, the cacao seeds are first fermented and then dried. During fermentation, important aroma precursors are formed. During later roasting, these continue to react and form a major part of the characteristic cacao and chocolate aromas.
Depending on the cacao variety, origin and method, fermentation usually takes several days. The subsequent drying reduces the beans’ water content and helps break down some of the organic acids formed during fermentation. This makes the cacao beans stable in storage and suitable for transport. At the same time, both steps decisively shape the later flavour profile.
Fermentation prepares the chocolate aroma
After harvesting, the cacao pods are opened and the seeds, together with the light pulp adhering to them, are removed. For fermentation, they are placed, for example, in wooden crates and are often covered with banana leaves.
At the beginning, only a little oxygen reaches the cacao mass. Under these conditions, yeasts become active above all. They use the sugar from the sweet pulp and convert it into alcohol and carbon dioxide, among other things. At the same time, enzymes and microorganisms break down the structure of the pulp so that it increasingly becomes liquid and drains away.
After about two days, a large part of the sugar in the pulp has been converted. The cacao mass is then turned regularly. This allows oxygen to enter and other microorganisms take on an important role. Acetic acid bacteria convert the alcohol formed earlier into acetic acid. This generates heat and the temperature of the fermenting cacao mass can rise to around 50 to 55 °C.
Important changes are also now taking place inside the cacao seeds. The seeds have absorbed moisture and initially started germination processes. Enzymes are activated that break down proteins and sugars into smaller compounds, among other things. These compounds form important starting materials for the aromas that are later created during roasting.
At the same time, polyphenols are changed and oxidised. As a result, the strong astringency of the fresh seed decreases and its colour becomes increasingly brown. As the temperature rises and the acidity increases, the seeds eventually lose their ability to germinate. However, the chemical and enzymatic reactions inside continue.
In this way, numerous aroma precursors are formed during fermentation. It is only during later roasting that they react further and contribute to the development of the typical cacao and chocolate aromas.
The duration of fermentation is crucial
Fermentation therefore means far more than the breakdown of the pulp around the cacao seed. How long and in what way fermentation takes place has a significant influence on the aromatic potential and quality of the later raw cacao.
Fermenting for too short a time can leave the cacao strongly bitter and astringent, with its aromatic potential insufficiently developed. Fermentation that is too long or not carefully controlled, on the other hand, can produce unwanted flavours. It is therefore crucial to tailor fermentation to the respective cacao variety and the conditions at origin.
Why drying is important for quality and storability
After fermentation, the cacao beans still contain a lot of water and organic acids. In order for them to be stored, transported and later processed, they must then be gently dried.
The usual target is a residual moisture content of around 6.5 to 7%. If too much moisture remains in the beans, the risk of mould and further quality losses increases during storage and transport, among other things.
Ideally, the fermented cacao beans are dried slowly in the sun and with a light movement of air. In tropical climates, however, the conditions for this are not always constant. Rain, high humidity and changing sunlight can make the drying process more difficult.
For this reason, covered drying houses with open sides are used in cocoa cultivation, for example. They protect the beans from rain while also allowing controlled air circulation.
During drying, not only water escapes. A portion of the volatile acids formed during fermentation is also reduced. In this way, the moist, freshly fermented cacao seeds become cacao beans that are suitable for storage and transport, while their aromatic potential remains intact for further processing.
Why post-harvest handling is so important for fine flavour cocoa
The genetic properties of fine flavour cocoa form the basis for characteristic aromas, such as fruity, floral, nutty or spicy notes. Whether these are later clearly perceptible in the finished chocolate depends largely on how carefully the cocoa is processed after harvesting.
Fermentation and drying are therefore crucial steps on the way from fresh cacao seed to finished single-origin chocolate. They can preserve and bring out the existing aromatic potential, but they can also impair it if the processes do not match the respective origin and cacao variety.
Post-harvest handling is therefore also an important part of our collaboration with our partners at origin. Knowledge of fermentation, drying and quality control helps to preserve the characteristic properties of the respective fine flavour cocoa as well as possible.
Find out more about our collaboration at origin under Direct Trade. Our article on terroir and origin explains the role of soil, altitude and microclimate in the taste of cacao. You can find an overview of our origins and their aroma profiles under fine flavour cocoa at Rausch.
