This was my first attempt at making apple-cider-vinegar at home. I did this all following a tutorial from YouTube. I simply cut a few apples and put them in a clean jar with sugar+water. I set the lid over the jar but did not tighten so as to allow some airflow. Then, I just kept it untouched for about two weeks.

Up until two days ago, there used to be messy white foam/scum on the surface. And the jar looked a little messy on the top due to that. Today I noticed it is all clean at the top, then when I looked closely I found these tiny maggots lurking all around the top of the jar.

white little maggots lurking on top of the jar

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Is this batch completely ruined? What must have I done wrong? Is it salvageable?

Am I right to think that some sort of tiny flies must have found a way inside the jar (since the lid was intentionally not tightened)? Also I don't see these guys below the surface.

  • Why do you have to add sugar when apples have sugar already? Why doesn't this turn into alcoholic cider instead?
    – Chloe
    Commented Oct 3, 2018 at 17:49
  • 3
    @Chloe I don't understand why sugar was added but unpasteurized apple juice will turn into alcohol, no added sugar needed. Roughly: alcohol is a byproduct of yeast and vinegar is produced by bacteria. I'm not sure why this was done with apple bits. Juice/cider would be my choice.
    – JimmyJames
    Commented Oct 3, 2018 at 19:38
  • 1
    @Chloe I was simply following the instructions given in this video Would anyone mind telling me how it should be made instead.
    – gurung
    Commented Oct 4, 2018 at 3:03

1 Answer 1


I wouldn't even try to salvage this. It's not worth it.

The two main problems I see are:

  1. You don't have enough liquid. There should be enough water and apple juice that apples can drown in it.
  2. Even with a lid on, there should be a gauze under or over it. Like in the old pictures of a jar with anything sweet.

Because those maggots probably originated from fruit flies (or regular flies) that were lured with the sweet scent. And you won't see them under the surface as flies don't lay eggs in water.

The foam/scum would be natural as your mixture started to ferment.

  • 1
    The apples were submerged in the liquid with the help of a bowl ( made of glass ). Gauza under a loose lid is a good idea. I will do it in the next batch. I am getting rid of this. Thank you.
    – gurung
    Commented Oct 3, 2018 at 15:51
  • 7
    Seconding that it's fruit fly larvae. Make sure the gauze is solid enough to keep fruit flies out, and you should be golden.
    – user69639
    Commented Oct 3, 2018 at 17:08
  • 2
    Yeah or even a paper towel.
    – Chloe
    Commented Oct 3, 2018 at 17:49
  • 2
    Another option is to get a brewing airlock. You can find these anywhere brewing supplies are sold for a couple of dollars. Just pop a hole in a lid to put the lock in, you can buy a little o-ring/gasket for the hole.
    – JimmyJames
    Commented Oct 3, 2018 at 19:42
  • 4
    @JimmyJames With a brewing airlock you will stop the influx of oxygen though. This will result in apple wine, not vinegar. You can take it off later to make vinegar from the wine, of course. But then you'll have to worry about the flies again. Gauze should be the best (and also cheapest) solution for OP's problem.
    – Kakturus
    Commented Oct 4, 2018 at 9:38

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