Plantation Crops

Methods of fermentation

Fermentation Fermentation of Cocoa beans is essential to remove the mucilaginous pulp, to develop flavour and aroma precursors, reduce bitterness, kill the germ of the seed and to loosen the testa. Among the various methods adopted for fermentation in different cocoa producing countries, Heap, Box Tray and Basket methods are considered as the standard methods.
Heap Method
• This method involves keeping a mass of not less than 50 kg. of wet beans over a layer of banana leaves. The banana leaves are spread over a few sticks to keep them a little raised over the ground level to facilitate the flow of sweating. The leaves are folded and kept over a heap of beans and a few wooden pieces kept over it to keep the leaves in position. The heaps are dismantled and the beans mixed the third and fifth days. It needs about six days for the completion of fermentation and the beans can be taken out for drying on the seventh day.
• Even though the minimum quantity of beans required for effective fermentation is 50 kg. a further increase in quantity of beans in a heap will be beneficial. However, heaps of more than about 500 kg. may be difficult to handle.
Tray Method
• Wooden trays of size 90 cm x 60 cm x 13 cm with battens or reapers fixed at the bottom with gaps in between, are filled with beans. Each tray can contain about 45 kg. wet beans. Six such trays are stacked one over the other and an empty tray is kept at the bottom to allow for drainage of sweating. After stacking, the beans of the top most tray are kept covered with banana leaves.
• After 24 hours of setting the stack of trays is kept covered with gunny sacking to conserve the heat that develops. There is no need for mixing the beans and fermentation will be completed in four days. On the fifth day the beans can be taken out for drying.
• The minimum number of trays required to be stacked is about six but as many as 12 trays can be used simultaneously.
Box Method
• Wooden boxes of 1.2 x 0.95 m x 0.75 m with holes at the bottom and sides of the box are filled with wet beans. These boxes can hold one M.T. of wet beans. The beans are to be mixed on alternate days. As the quantity of beans is high, this is best done by changing the beans from one box to another at the time of mixing. This would necessitate having a minimum of three boxes.
• Wet beans taken for fermentation should be sufficiently ripe so as to separate the beans form the polacuta and husk easily. Minimum quantity of wet beans for a normal fermentation is about 100 kg. The duration of fermentation is commonly for 3-5 days i.e., 72-120 hrs. Fermentation over 120 hours will cause loss of chocolate flavour and development of off flavour.
Drying & Storage
• The fermented beans can be dried either in the sun or by artificial means. Sun drying can be done in thin layers of 2 - 3 cm. depth and stirring from time to time. When the beans are dried properly, they produce a characteristic cracking sound on compressing a fistful of beans in the palm.
• The more scientific method is to use moisture meter. The dried beans after cooling maintaining 6 -8% moisture should be cleared before storage. The fruit broken, shriveled and other extraneous material are removed. The cleared bags are kept on a raised platform of wooden planks.

  However, box and basket methods are recommended.
What ever be the method adopted care must be taken

1) Immediate fermentation : To put the beans for fermentation immediately after taking out of the pods.

2) Proper insulation : Fermentation mass need to be provided with proper insulation for retentation of temperature

3) Proper facility for aeration of bean : Adequate facility for aeration beans must be made.

 4) Drainage of sweat liquor.