Understanding Expiration Dates

Every time we go to eat an item it's almost always labeled with some type of date on it. Whether it says "sell by", "best by" or "who knows why."  Actually that last one is just a joke but nethertheless often times it's not so easy to know what exactly these dates mean.  If your interested in learning more about expiration dates and how this whole thing works go ahead and check out this interesting article at the following link: http://www.slate.com/id/2244249?yahoo=y