Parchment coffee that is ready for storage should ideally have a moisture content of about 11%. The higher the moisture content, the quicker the decline in quality. Parchment coffee has the protective parchment layer intact; hence it can be stored for up to one year. Once this layer is removed by hulling, the bean is exposed to the action of micro-organisms, and has the potential to become infected by bacteria, resulting in mouldy beans. Hence, green beans are not suitable for long-term storage. Thrashing should only be done when the bean is ready for exporting.
While storing coffee, it is important to minimize the effect of high temperatures and high humidity on the beans. This is achieved by storing the parchment coffee in bulk, such as in large bins, silos or organized piles of coffee bags. This way, the surface area to volume ratio of the coffee beans is reduced, and hence the exchange between the coffee beans and the ambient air is minimized.
The storage area must be free of smoke to avoid contamination and fire; free of insects and animals (such as rats). They should also be located away from other processing facilities such as fermentation tanks, and composting areas, to avoid bacterial infection. It is imperative that the temperature, humidity and the moisture of the storage area be periodically monitored.
Many defective beans are the result of poor storage practices. Re-wetting of the beans during storage can result in spongy, mouldy or blotchy beans. If stored for an extended period of time or under high temperature and high humidity, the beans can become pale. In short, storage is a very crucial process in coffee processing.
“An Introduction to Good Manufacturing Practices for Post Harvest Processing of Arabica Coffee in Vietnam” - Jan. C von Enden.
Coffee Research Institute
Intelligentsia Coffee & Tea, Inc
INeedCoffee – The Coffee Mill
On the Road to Quality. Made by Kraft foods Germany, Vietnam Coffee Cocoa Association VICOFA and Dtsch. Gesellschaft für technische Zusammenarbeit (Gtz).
Mr. Jan C. von Enden
EDE Consulting Asia Pacific