Green coffee beans do go bad, but if maintained in the proper conditions green coffee beans can last about a year. After a year, the green coffee beans will begin to degrade and it will affect the flavor becoming more bitter, acidic, and stale. There are a few factors that influence the shelf life of the coffee.
Green coffee beans typically have a 10% – 12.5% bean humidity, and it is important to maintain it at these levels in order to preserve the qualities and characteristics of the bean. It is recommended to store at 50% – 65% relative humidity (RH). According to the International Coffee Organization (ICO), green coffee beans stored at high RH levels will increase the speed of quality deterioration and fungal development.
Jute bags or sacks have been used to transport and store green coffee beans for a very long time, but unfortunately, jute sacks do not protect from externalities like heat and moisture. Nowadays, it is common to use hermetic inner liners like GrainPro bags. It is an added cost, but they are well worth it to preserve the quality and freshness, and much appreciated by roasters.
Green coffee beans are recommended to be stored at room temperature or between 18° – 25°C (64.4° – 77°F). Store the coffee in an area where it is not too hot or too cold and the temperature remains stable.
Sunlight is an enemy of green beans. Avoid bright light as it accelerates the coffee bean’s deterioration. Store in a dark and cool location.
Green coffee beans are porous and absorb aromas and flavors very easily. This means that green coffee cannot be stored next to something that emits strong smells; hermetic packaging helps.