Coffeeclues

Coffee processing is a method that involves the conversion of raw fruit to green coffee. This article talks about the two methods involved in processing of coffee.

Coffee Processing- Methods
Dry method

• It is one of the simplest and oldest method and makes use of less machinery. Firstly, cherries are cleaned and sorted out to separate the overripe, unripe and damaged cherries. This is done by a process called as winnowing. This procedure is performed using a sieve.
• Once all the above mentioned procedure has been carried out, the beans are spread in the sun on large brick or concrete patios. Cherries are turned by hand regularly to promote even drying. It takes about 4 weeks for the cherries to loose 12.5% moisture content. In case of large scale plantations, machine drying is done after they have been dried in sun for few days. This ensures faster drying.
• Drying is the most vital step during processing. If over dried it leads to the cracking of beans. Cracked beans are not desirable and are considered as defective. If proper drying is not done moisture is retained on the surface of the beans. Due to retention of water on the beans it is prone to fungal infections. Drying is followed by grinding process.

Wet Method

• This method makes use of water and specific equipments. In this method, quality of beans are well preserved. It ensures good quality coffee. As in the case of dry method, cleaning and sorting of cherries is done in this method to remove unripe beans and dirt. Cleaning of beans is done in a tank with flowing water.
• Now, pulp is removed from it. One of the major difference between wet and dry method is, in wet method pulp is removed before drying. Machines are used for pulping. These machines separate flesh to one side and the cherries with mucilaginous covering on the other side.
• Now the beans are subjected to fermentation to break down the mucilage layer surrounding them. It takes about 36 hours for fermentation process. Factors such as enzyme concentration, thickness of mucilage also affects the fermentation process. Once the fermentation has been carried out, the beans are washed and subjected to drying. Drying may be under sun or by use of a dryer.