Updated: Aug 21, 2021
Cocoa bean is known for its distinctive and eccentric sensory and melt-in-mouth characteristics, but do you know that there are various types of cocoa beans and more than 600 odour active compounds that contribute to this chemistry of cocoa aroma. Other factors which contribute to the uniqueness of the cocoa beans are the various reactions occurring after the harvest of the raw beans, the genotype of the cocoa bean, environmental conditions in which it is grown and kept post-harvest, farming practices, processing and manufacturing.
The demand for cocoa beans has been ever increasing due to its vast application especially in the chocolate industry. The production of cocoa is vastly done in West Africa accounting to almost 70% of the world production followed by Asia (15.6%), Latin America (14.1%),
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The quality of cocoa beans vastly depends on the flavour and the aroma of the bean. There are many varieties of cocoa beans. Let us take a look at them.
Forastero: - These are cocoa beans cultivated since historic times, majorly in West Africa and South America. They have a vigorous property with a strong chocolate flavour having great variations. Forastero type of cocoa beans is used in the manufacture of cocoa mass, cocoa powder, cocoa butter, milk/dark chocolate and form 90 % of the total cocoa output in the world every year.
Criollo: - These cocoa beans are grown in Central America, Venezuela (largest producer), Madagascar, Sri Lanka, and Samoa and are very rare due to disease susceptibility. It has a low resistance to pest thus low yields, but the beans are very highly aromatic and has a mild nutty, earthy, and flowery tea like flavour.
Trinitario: - These types of cocoa beans are the hybrid of Criollo and Forastero type of cocoa beans. They have higher yields, less susceptibility to diseases and has a strong chocolate wine like flavour.
Nacional: - They are grown in the area Ecuador, which produces arriba - aromatic, floral, spicy and green flavour.
Let us take a look at how the cocoa beans are processed:
Fermentation of cocoa beans is done in two main phases which helps in the pulp removal, flavour formation, death of beans, colour development and reduction of both bitterness as well as astringency. There are various factors that affects the rate of fermentation like method of fermentation, cocoa bean genotype, duration of fermentation and its speed.
Phase 1 - Anaerobic phase which takes place in the first 24h to 36h of harvesting. Here the beans are introduced microorganisms which helps the beans undergo alcoholic fermentation catalysed by yeast.
Phase 2 - This phase takes place after 48h to 96h of harvesting where the yeast activity is stopped leading to the growth of lactic acid bacteria which gets converted to the acetic acid bacteria. The formation of acetic acid bacteria is necessary for the formation of flavour.
A period of 6 days is considered ideal for fermentation of cocoa beans to get the perfect flavour formation. The duration of fermentation highly affects the pH and temperature of the beans affecting the flavour. Thus, overfermentation may result in increased pH value, blackening of seeds and loss of flavour or a hammy flavour.
The main purpose of this step is to reduce moisture content down to 7%, hamper excess fermentation, prevent bean damage by mold contamination, reduce acidity bitterness and astringency and give that distinctive flavour and colour.
There are three types of drying
1. Sun drying - It is preferred as it give a more characteristic chocolaty taste.
2. Artificial Drying - It may create a smoky, hammy and gasoline flavours.
3. Step-up-dried – This process gives the best flavour profile.
Incomplete drying harms the flavour the of the beans creating string hammy off flavours.
This is the most important step of cocoa bean processing. It has the following role
- Roasty flavour is imparted
- Enhanced texture
- Removal of unwanted desirables
- Further reduction of moisture content
- Reduction of astringency
- Improved flavours as a result of Milliard’s reaction
Roasting can be performed in three ways Bean Roasting, Nib Roasting, Liquor Roasting. The choice of method is dependent on the variety of cocoa beans and the required flavour. Over roasting should be avoided as it causes a burnt taste and other off flavours.
This process is also called Dutching. The process involves treatment of cocoa mass with alkali. This process can also be performed before roasting. The significance of this step is as follows:
- Improves colour of the beans
- Enhances the flavour
- Increases dispersibility of the powder of these cocoa beans
- Reduces astringency
- Provides a deeper shade of brown to the cocoa products formed from these beans
This is the final step of cocoa processing which involves stirring of beans at higher temperatures to create the perfect flavour and smooth texture of the chocolate formed from these beans.
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