J. Kenji López-Alt: The Food Expiration Dates You Should Actually Follow (NYT)
Food product dating, as the U.S. Department of Agriculture calls it, is completely voluntary for all products (with the exception of baby food, more on that later). Not only that, but it has nothing to do with safety. It acts solely as the manufacturer’s best guess as to when its product will no longer be at peak quality, whatever that means.