About 2-3 months ago I decided to start my own batch of vinegar. I started with some Braggs apple cider vinegar which contains the mother, and I added some old wine and some fruit juice to the mix. I kept it in a dark and warm place, as per instructions online. A few layers of cheesecloth were placed on top to allow it to air, without letting anything else get into it.

When I recently opened it, I found a layer of what appears to be a yellow-orange mold on top. There are also some small worms or maggots living on the top, but that doesn't seem as problematic to me.

enter image description here

As you can (sort of) see in this picture above, there is definitely a mother at the bottom. The mother has grown since I last saw it. I am not sure what to think about that top layer though. Is the vinegar batch completely spoiled?

Picture #2 (a closer look at the top)

enter image description here

  • 2
    I don't know enough about making vinegar to say one way or another whether the mold is OK, but I find it odd that you're concerned about about the mold, but you're OK with worms and/or maggots. From a food safety perspective, you're right, the mold is more of a concern...but still?? Interesting...
    – Jolenealaska
    Dec 14, 2014 at 22:27
  • Oh my goodness, have you seen how many views this post has already? (6760)
    – Doug
    Dec 15, 2014 at 18:01
  • I had mold on a vinegar I was making from a mother and apple juice. I got the mother from an all natural, unpasteurized apple cider vinegar. I added all natural apple juice. A scoby formed on top but after two weeks mold grew on top of my scoby. I couldn't scrape the mold off the scoby and threw the batch out. Mar 27, 2017 at 16:52

3 Answers 3


Great question.

First off, the mold. This is nothing to worry about, you should be skimming it off but as far as Vinegar creation it's normal and to be expected.

These "worms" have a name :-) Turbatrix Aceti (a.k.a Vinegar Worm) you can read more about them here -> wiki/Turbatrix_aceti

Why is that mold there? Well if you think about the fermentation process. It's just thousands of bacteria 'eating' your 'mother' now they have to produce something as a byproduct which is the mold you see on the top. Get rid of it and leave it to carry on.

If you see a scum forming on top, don’t disturb it; this is the mother. Eventually the mother will sink toward the bottom and continue its work. However if you see mold forming on top, by all means skim that off. Mother isn’t moldy; it’s scummy.

Source: http://www.rural-revolution.com/2013/07/making-fruit-scrap-vinegar.html <- Well worth a read since you're making vinegar :-)

Mold = Bad (Clean it off) Froth = Good (Leave it alone til' it turns to mold.

Question: Is the vinegar batch completely spoiled? Answer: No.

  • Interesting stuff. Should he filter the worms from the vinegar now as he skims off the mold? Is it possible to filter, yet keep the mother?
    – Jolenealaska
    Dec 14, 2014 at 22:48
  • From what I can tell the worms are harmless, by all means when scraping off the mold you could try and fish our the worm's. You'll probably find they will return. I wouldn't recommend filtering the liquid as doing so will disrupt and probably destroy the mother. The OP states the vinegar is 2-3 months old. It is possible he/it is actually now ready for the next step where a complete filter would be necessary anyway?
    – Doug
    Dec 14, 2014 at 23:10
  • 8
    "It's just thousands of bacteria 'eating' your 'mother' now they have to produce something as a byproduct which is the mold you see on the top." - I'm a little confused. Mold isn't a bacterial byproduct, it's fungus.
    – Cascabel
    Feb 3, 2016 at 0:16
  • @Jefromi +1 I'm confused about that statement too. Mold & Bacteria are different organisms entirely. One cannot be a byproduct of the other. Feb 3, 2016 at 7:03
  • Sorry, it's not mould at all. It's all by product.
    – Doug
    Feb 3, 2016 at 7:13

I have salvaged both vinegar and kombucha from mild mold by removing what I could, increasing stirring to twice daily and watching it more carefully and removing the very first signs of opaque, white , blue green or furry. I also spray the top with straight vinegar. Once the mixture gets acidic enough the mold won't grow. If it's kombucha you need more starter from your last batch to get the ph down enuf to prevent mold.


I have made several batches of vinegar and have also noticed mold - usually light colored - most dramatically on the raspberry vinegar that I made. If i just leave the mold alone it appears to be consumed or disappears after a little bit. It may just have been the scum that precedes the mother but it always disappears.

Not the answer you're looking for? Browse other questions tagged or ask your own question.