Food preservation--in other words, extending shelf life--has been a widely-practiced human endeavor since the days of cave people.  (Forget that sexist term "cave men.")  According to the website PartSelect, cave folk who lived in cold locations froze fish, seal meat, and other small animals by storing them on ice.  In warmer climates, drying was the ancient method of choice for food preservation. Later, to freezing, drying, and fermenting, the Romans added pickling and canning. 

In modern times, science has provided additional ways to extend shelf life, especially techniques, currently widespread, that can keep foods fresh longer in the refrigerator. Now, scientists are working on ways to extend the shelf life of foods that are customarily refrigerated, making them safe and tasty at room temperature for longer periods of time. Read on to discover the "supersandwich" with a shelf life, at room temperature, of 3-5 years!  But let's start with the somewhat high-tech processes that most consumers come in contact with regularly, though they may not realize it.

“Use by,” “best by” and “sell by” dates (commonly referred to as expiration dates) are supposed to help consumers make good decisions about what foods to purchase, consume, and discard.   But many folks find them more confusing than helpful.  Moreover, these food expiration dates create anxiety, causing consumers to throw out a lot of perfectly good food.  

Fearing food poisoning, many consumers follow this familiar advice: “When in doubt, throw it out.”  That’s the most worry-free solution, but it certainly isn’t the thriftiest.