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Jan 29, 2009 04:05 PM

Does vinegar ever go bad?

I just found a old bottle of fancy schmancy Italian vinegar, shoved in the back of a cabinet. We're talking as much as seven years old. It looks and smells fine, though there is some sediment that has settled in the bottom of the bottle. It's fine to use, isn't it?

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  1. i'd use it if it tastes ok. i can't see what would go "bad"....

    11 Replies
    1. re: alkapal

      I make vinegar, have never had it go bad or heard of it going bad.

      Unfiltered vinegar can develop vinegar eels, even then it's still okay to use. If you don't like the look of the sediment, filter it through cheese cloth or a coffee filter.

      1. re: Demented

        Vinegar eels? Is that the "film" I'm talking about. It's a semi-solid product. I don't know how to describe it.

        1. re: Demented

          ah, an eel! i see it!

          demented, would you please weigh in here on this thread, re my query on vinegar, yeast, etc.?

          1. re: alkapal

            I misspoke, filtering has nothing to do with it. Vinegar eels (and mother of vinegar) can only form in vinegar that has not been pasteurized.

            Mother of vinegar is a combination of cellulose and acetic acid bacteria, that forms a jelly like membrane on top of vinegar in a cask or crock.

            Acetic acid bacteria convert alcohol into acetic acid in much the same way yeast convert sugar into alcohol.

            Vinegar eel's are a type of small animal that can develop in raw vinegar, not really something you want in your vinegar crock, but they can be filtered out.

            Commercial vinegar is pasteurized, to prevent the formation of mother of vinegar and vinegar eels.

            1. re: Demented


              How do you know so much about vinegar??? I truly thought you were kidding about "vinegar eels"...but just looked it up and they really do exist. I'm just amazed that anyone knows that much about vinegar!

              1. re: DaisyM

                Internet, amazing what you can learn. I actually knew some of that. But I have to admit. To learn it I probably looked it up before myself, lol.

                1. re: kchurchill5

                  I'm going to throw out all of the old bottles of vinegar...I fear the vinegar eels!

                2. re: DaisyM

                  I've been brewing beer, making mead, wine and vinegar for years.

                  You needn't worry about the old vinegar, if you bought it in the store, it was pasteurized before it was bottled. Thats the law.

                  I noticed these little worms swimming in one of my vinegar crocks one day, a little research lead me to information on vinegar eels.

                  I strained that batch of vinegar, brought it to a boil, let it cool and used it with no ill effects.

                  1. re: Demented

                    I just want you to know that I completely in awe that you knew about vinegar eels AND that they even exist!

                3. re: Demented

                  Wow. I don't think I'll ever look at vinegar the same way again. Who knew? I think I could win a few bets with that piece of knowledge!

                  1. re: Demented

                    vinegar eels are not animals, to be sure...

            2. I've had the experience of red wine vinegar (don't know if that matters) developing a "film" down at the bottom of the bottle. But it was alright for cooking I hope) which was all I was using it for.

              1. Taste ... if ok use. I have had the same thing.

                1. My Cook's Illustrated just came today. They say commercially made vinegar keeps indefinitely. The sediment is harmless cellulose that can be strained throug a coffee filter set inside a fine mesh strainer. The Vinegar Institute concurs.

                  1 Reply
                  1. re: PAO

                    "The Vinegar Institute"......Such a body exists?

                  2. I wouldn't say indefinitely, I had some once go bad, but I just taste. If ok ... there you go. I keep mine in the fridge too. Just me.