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Jan 31, 2004 09:11 AM

Can mayonnaise be stored at room temperature?

  • d

I remember seeing on another board a discussion about that topic. It was said, that you can leave mayonnaise, that has been opened, in your cupboard and it is shelf stable. Has anyone else heard of this? Is it true?

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  1. j
    JK Grence (the Cosmic Jester)

    The two main ingredients in mayo are oil and eggs. The oil doesn't present much of a problem, but you certainly wouldn't want to keep eggs on the counter for very long. Stick the mayo in the fridge once you have opened it.

    4 Replies
    1. re: JK Grence (the Cosmic Jester)

      Ditto anything made with mayo in it. If you (Dawn) are going to be selling things at farmers' markets you should know this...

      1. re: suzannapilaf

        (Suzannapilaf) I was asking the Chowhound board a question that I have wondered about since I saw a discussion about it on another board. That does not mean I do not practice or know safe food storage procedures. As someone selling to the public (or feeding my family), I always err on the side of extreme caution. Anyone with a food handler's license knows, or should know, the temperatures that foods must be stored at when selling commercially. That knowledge explains why I have two shelves of cryovac and blue ice in my freezer, that I use when selling at Farmer's Markets.
        Commercial mayonnaise has a pH of approx. 3.0, which makes it a high acid food. That is why some health inspectors no longer test the temperature of crocks of mayonnaise during inspections in commercial kitchens. That is also why I asked the question to begin with.
        I found your response to me to be a bit derisive and hope your future responses might be a bit more helpful. Thanks!

        1. re: dawnie2u

          Worked for a summer in a salmon cannery in Alaska and lived without electricity, et al. We kept the mayo out with everything else on a shelf in the one room cabin we lived in and never got sick. On the other hand, here at home we keep it in the fridge after it is opened. Better safe than sorry.

      2. re: JK Grence (the Cosmic Jester)

        Speaking of eggs, several years ago I spent a long vacation in Costa Rica. During my stay there I noticed that grocery stores kept their fresh chicken eggs at room temperature; they were never refrigerated. I was a bit weary to eat the eggs at first but I nor any of the people I was traveling with ever got sick from the eggs.

        What's more I visited a commercial chicken place when I was there (the guy who was renting us the house owned the place so we went to visit out of curiousity)
        The place was huge and there were tables and tables full of egg trays all kept at room temperature. We travelled pretty much all over the country and this seemed to be the norm everywhere.

        Since that experience I am not too paranoid about egss that are accidentaly left out of the refrigerator.


      3. Well, the label says to refrigerate it, and I can personally attest to the fact that if you forget an opened jar on the counter overnight it starts to sort of melt and separate around the edges and looks pretty funky. No evidence as to what it tastes like at that point -- too scary-looking.

        1. Isn't it the mayo component getting old (i.e. bacteria-full) that sickens people eating bad potato salad?

          1 Reply
          1. re: bob192

            Since posting this question, I have looked around a bit and found out a few things. Commercial mayonnaise is actually a high acid food and actually helps to deter the formation of bacteria in foods. It is the low acid foods that when stored improperly cause the food poisoning. Here is one link I found.


          2. I have heard that mayo is shelf stable UNTIL you double dip with the knife adding breadcrumbs, etc.

            But it always helps to go to the source (linked below)

            "How should Hellmann's® Mayonnaise be stored?
            Unopened jars of mayonnaise and mayonnaise dressing may be stored at room temperature. Once opened, mayonnaise should be refrigerated to maintain its flavor. Storage temperature affects product quality. High temperatures will accelerate loss of fresh flavor; exposure to freezing or near-freezing temperatures can change the consistency, texture, and thickness."


            1. My grandmother has kept her mayo in the cabinet at room temp with no ill effects to the family for over 70 years. I don't follow this practice myself. However, in my home we don't refrigerate our ketchup or mustard, which some of our friends find odd.

              1 Reply
              1. re: Melissa

                i don't think ketchup *needs* to be refrigerated (my mom doesn't do it either) but i think it tastes more vinegary without it. am i imagining this?