I inadvertently walked in on a conversation, well let's call it what is was, a debate on Mayonnaise between two of my coworkers, Heather and Christina. It wasn't a heated debate, but it was interesting. They were debating about whether or not Mayonnaise goes bad or expires. Heather says that it doesn't go bad (ever) if it's kept in the refrigerator. Christina says it does go bad and that you need to throw it out after the best used by date. Christina's reasoning is because of the egg in the Mayonnaise (though according to Wikipedia only about 6% is egg and usually egg yolk) I personally agree with Heather, once you've opened the jar and put it in the refrigerator, you're golden until it's gone, after all the "best used by date", is just a suggestion. What are your thoughts? And by the way it's only Best Foods Mayonnaise in my house.