What is meant by the shelf life of food?
The shelf life of food refers to how long the food will remain in good quality. This is different than the expiration date. A food can be beyond its shelf life and still be safe to eat, however, it might not taste very good.
It depend on certain types of food and the condition of surroundings. For Food A, If its humid, wet, dark, dusty, warm and in unsealed container, mold/bacteria growth will be enhanced and the food's shelf life is shorten. For Food B, If its humid, wet, dark, warm and in air-sealed-tight container, mold/bacteria growth will be slower and the food's shelf life is much longer than the food A. About the same rate for For food…
According to the following link the shelf life of crackers after the package has been opened is about 1 month. This will vary depending on the ambient room temperature and how the package is sealed. If it does not contain a ziploc seal (which keeps out excess oxygen) you will most likely have a shorter shelf life and food will appear stale. http://msnbc.com/onair/nbc/dateline/food/shelf.asp