What exactly are “sell by” or “best by” dates? Maximizing the shelf life of your groceries can seem a little mysterious. There’s also a lot of confusion about the point when a food becomes unpleasant or unsafe to eat. The truth is many foods last much longer than you may think, and proper storage can keep them edible for even longer. Follow these general strategies and tips for making foods last longer so you can save time, money and aggravation.