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Feb 28, 2007 04:49 AM

Mayonnaise - Does it expire?

I bought a jar of mayonnaise last July to make a chocolate cake. I haven't used the mayo again, because I hate mayonnaise.

My question is whether the mayo is still good. It's just been sitting in my refridgerator for the past 9 months. Might it go bad? How would I know?


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  1. Yes it expires. I've never seen mayo that didn't have a printed exp date. I wouldn't use 9 mo old mayo but if there isn't visible mold, it actually is probably fine.

    1. Question...if you hate mayo why don't you just toss it?

      1 Reply
      1. re: lucyis

        Well, I wanted to make another cake with mayonnaise. Otherwise, I'd never use it. It makes good cakes.

        I didn't think to check for an expiration date. I generally just try to avoid it.

      2. Smell it. It gets a rancid sort of aroma and is a little yellowish in color.

        1. You bet it expires! Mayo contains two main ingredients, raw egg and vegetable oil, plus a bit of salt and other flavoring. The egg keeps longer than you'd think thanks to the preservative action of the salt and oil, but not indefinitely.