I recently ordered a jar of Just Mayo from an online store and was sent a bottle that has a sell by date for about a month ago. The obvious complaint aside, it got me wondering how likely it is that such a product would actually be unsuitable for consumption. I mean, products like Just Mayo or Vegenaise don't have any eggs or dairy in them (its kind of their selling point). So they wouldn't 'turn' nearly as quickly as traditional mayonnaise, right?

My question is, how long would it take for an egg-free mayo to actually go bad? I've seen similar questions here about condiments and sell by dates, but whenever it comes to mayo, the eggs always come up as a key factor and that's not an issue with the products I'm talking about.

Here are the ingredients of Just Mayo: enter image description here

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    What is its normal shelf life for these products? Exceeding the expiration date by a month on a product that expires a month since manufacturing date is way different than exceeding it by a month with one that expires 3 years after manufacturing.
    – SF.
    Jan 22, 2019 at 11:06
  • How is the food starch modified? I wouldn't expect <2% pea protein to thicken oil. May 22, 2019 at 23:12

2 Answers 2


I couldn't find a previous answer specific to sell by dates and condiments. Most condiments, mayo with egg included, are made safe by creating an inhospitable environment for bacterial growth. The addition of acids (i.e, vinegar, lemon) or other "preservatives" accomplishes this. Sell by dates are usually an indicator of quality, not safety. Items such as this are safe for a very long time after the expatriation, especially if unopened, though the quality (taste and consistency) degrades. Once opened, you have the opportunity to introduce bacteria and spores to the contents. Again, bacterial growth will be inhibited by the product itself. The most likely problem would be mold growth. If this occurs, discard.


I do not think that there is a definite time period that can be given for this question. In the UK, and I think this is the same for all of Europe, foods that do not spoil because of microbes are given a minimum expected lifespan. Companies fully complying with the law do not need to invest any more money in, i.e. bother to research, finding an upper limit.

Once this date has passed it becomes a game of chance - a certain percentage of the same batch of foodstuffs spoil after a certain time. As time goes on this percentage increases. This is dependent on many things, such as cooking process, just as much as ingredients. Unless someone buys a large batch of Just Mayo and samples them until they spoil (usually by taste testing), then releases their findings, I think that no suitable definitive answer can be given.

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