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Apr 9, 2010 12:57 AM

Homemade mayo

How long does it stay good for in the frig?

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  1. According to Alton Brown, keep it on the counter for an hour or two, then stick it in the fridge for up to a week. You actually want to leave it out for a little while before refrigerating. Mayonnaise is quite acidic, and the acid kills off salmonella from the eggs.

    3 Replies
    1. re: JK Grence the Cosmic Jester

      Thanks! I don't quite understand why store bought mayonnaise stays good so much longer, but when it comes to mayo I don't want to risk it.

      1. re: aMillionDreams

        Store bought commercially produced mayo is made from pasteurized eggs, (heated to 140*) not fresh, like yours.
        The fresh stuff goes off pretty quickly, make it in small batches and plan to use up in 3-4 days.

        "the acid kills off salmonella from the eggs" It's more like it helps to kill, depending on the strength of the solution. The amount of vinegar you would normally use in a mayo recipe isn't going to do it.

        If you have concerns about using raw eggs, purchase pasteurized egg yolks. I've read recently of a technique for pasteurizing your own yolks, with a little vinegar or lemon juice, in a microwave, until the egg yolk temp is 140*, held at that temp for three minutes. I can't vouch for this technique, but it was an interesting read. Google "pasteurized egg yolks" for more info, if you're interested.

        1. re: aMillionDreams

          Commercial mayonnaise also uses flavorless stabilizers, starchy substances that allow emulsions to hold that magical semiliquid state long after your homemade stuff would collapse in a puddle. This allows them to use pasteurized egg, which I used to use back when I could get it easily; it made good mayonnaise, just not good FIRM mayonnaise.

          I have been led to understand that it's the whites that can harbor salmonella, not the yolks. Anyway, I've kept my own mayonnaise up to two weeks, and so far so good. I just don't feed it to pregnant women...