What term refers to the length of time a commodity can be stored without becoming unfit for use?

The term that refers to the length of time a commodity can be stored without becoming unfit for use is known as shelf life. Shelf life indicates the period during which a product maintains its intended quality and safety when stored under proper conditions. This concept is crucial in food preparation and nutrition because it helps consumers determine how long they can keep food items before they risk spoilage or degradation in quality.

The other terms listed are related but have specific meanings: an expiration date typically indicates the last date a product should be consumed for safety reasons; a best before date suggests when a product is expected to be at its best quality but does not imply safety if consumed thereafter; and a use by date is similar to an expiration date, focusing specifically on perishable items that should not be consumed after that date. Shelf life encompasses the overall storage duration for quality assurance, making it the most appropriate term for the question.