Super Mayo?

My GF heard that you can leave mayo out and it will not go bad because it has so many preservatives in it. I don’t agree. I get rid of it if it sits out for an extended period of time. Anybody know anything here?

Interesting…according to Hellman’s mayo will not cause food poisoning.

I was going to say that mayo is a breeding ground for bacteria, because homemade mayonnaise usually is (along with any other raw egg-yolk-based sauce.) But I guess the commercial products are OK.


apparently, it’s never the mayo going bad in potato salad. mayo’s too acidic. it’s the potatoes. who’da thought?


I think we had a thread on this a while back, may have gotten lost. I believe the general consensus was that store bought mayo won’t go bad on the shelf, as long as it isn’t contaminated with other stuff. Little pieces of tuna fish, or chicken, or any other junk that can get in there when you spoon out the mayo, will contribute to it going bad.

As a result, keeping mayo in the fridge is probably a good idea.

Exactly. Mayo has plenty of nutrients, but almost no water - it’s all tied up in the emulsion. So mayo - by itself - doesn’t support bacterial growth very well. However, even tiny amounts of contamination, like bits of food, can provide enough water for growth. And since mayo is made from eggs, it’s potentially contamintated with Salmonella, which could take advantage of that water just fine.

Staph aureus is the other major concern with potato salad, but that comes from human contamination.