What Are Vingear Eels and How To Deal With Them

When I first heard about vinegar eels I have to admit I was pretty discussed. I instantly went to check all of my brewing kombucha to make sure I was eel free. But after doing some research, I feel much better about things.

So, what are vinegar eels?

Despite the name, vinegar eels have no relation to eels whatsoever. They are actually small nematodes called Turbatrix aceti that feed on the bacteria and yeast culture used to produce vinegar. Technically, they are harmless and non-parasitic, but that doesn’t mean we should ignore them. If you aren’t careful, there is a chance they can end in up your kombucha. Let’s make sure that doesn’t happen, shall we? 

Before we get into how to spot, get rid of, and prevent them, a brief introduction is in order.

Everything You Didn’t Want To Know About Vinegar Eels

Before we get into the details I should first mention that there is no need to panic when it comes to vinegar eels. For starters, finding vinegar eels in kombucha is incredibly rare. We’ll get more into the specifics down below, but there is no need to run to your kombucha and check.

Now than, what are these pesky nematodes and why are they trying to get into my kombucha?

As I mentioned in the intro, they are microscopic, worm-like nematodes that are usually found in raw vinegar. They actually aren’t after the vinegar itself. Instead, they feed off of the bacteria and yeast that are used to produce the vinegar in the first place.

Are you thinking what I’m thinking?

The combination of bacteria and yeast is the exact thing that we brew our kombucha with! So it’s no surprise that it’s possible to find vinegar eels hanging out in our batch of kombucha.

Are vinegar eels present in all types of vinegar?

The answer is no. I’ve done some research and I’ve found out that all vinegar is put through a pasteurization process that kills the bacteria and yeast once they’ve done their jobs. This cuts off the food supply for the vinegar eels and stops them from hanging out in almost all types of vinegar. Except one: raw vinegar.

As you’ll see below, raw vinegar (raw apple cider in particular) is the main culprit here.  They are typically around 1/16th of an inch long and feed on the bacteria of apples, so apple cider vinegar is a great source of these pesky criters.

Because they are so small, they make the perfect food for baby fish. Thus, they are commonly grown at home to provide the first meal for newborn fish.

Are Vinegar Eels Bad For Me?

Luckily, the answer is no. The FDA considers them harmless to human beings. If you’ve somehow managed to drink a few there is no need to be rushing off to the emergency room. However, any vinegar eels found in commercial products is still objectionable and is grounds for a recall.

As gross as it may be, they will simply pass through your digestive track without you noticing a thing.

And while they may not be necessarily bad for you, they are very harmful to your scoby. The hungry little microworms love the feast on bacteria and yeast. In other words, the exact thing your scoby is made of.

Are you trying to say these little worms are eating my mother scoby? 

Unfortunately, yes. This is the main reason (other than them being totally gross) we need to keep them out of kombucha.

So, you may be asking: how am I going to see these worms in the first place?

How Can I Spot Vinegar Eels?

In many cases, vinegar eels will be found in clumps, floating approximately ¼ inch from the surface of a liquid. They like to hang out close to the top because this is where the most oxygen is. This is one of the reasons why they are so popular when it comes to feeding baby fish – they hang out at the surface where fish can easily snatch them up.

The easiest way to detect vinegar eels is to take your kombucha to a dark room and shine a flashlight on one section of your bucha. Any worms present will begin to wiggle towards the light and you should be able to spot them easily.

You will likely also be able to see them clumped on the surface with your naked eye. You should also be able to see a few of them sticking to the side of your glass vessel if you shake the kombucha around a little.

Are There Any Signs My Kombucha Has Worms?

While you will likely spot them first, there are a few characteristics I’ve come accross during my research you should be keeping an eye out for.

  1. Any abnormal disfigurement of your scoby – while every scoby will come in different shapes and sizes, if you start seeing your scoby shrivel, or if it looks like it’s wasting away, this may be a sign you have vinegar eels.
  2. Your brewing rate begins to slow – this makes total sense. The worms eat the bacteria and yeast, the bacteria and yeast make the kombucha. If the numbers of bacteria and yeast start to drop, the rate of your fermentation will slow.
  3. Mold – the bacteria and yeast produce the acidic environment that is the first defense against mold. If the bacteria and yeast are weakened, this results in a perfect opportunity for mold to develop on your kombucha.

While these are signs that vinegar eels may be present, they are also the symptoms of other things that have gone wrong during your brew. Don’t automatically blame worms. It’s best to check with the flashlight method to make sure.

The best way to deal with worms is through prevention. Here’s the best way to make sure you never find vinegar eels swimming in your kombucha.

How Do I Prevent Vinegar Eels?

The easiest way to prevent vinegar eels is to avoid raw vinegar at any costs. This applies both to your starter liquid as well as your scoby. If your scoby was raised in contact with raw vinegar (say from the person you received it from) your entire brew may be at risk of vinegar eels.

If you also have received a scoby from a friend who already had vinegar eels then there is a good chance your buch may be spoiled as well.

Additionally, if you’re someone who likes to use natural cleaning products and have been using raw vinegar to clean your kombucha supplies you may want to double check your brews. Here are a few ways you can prevent these microworms from invading your kombucha:

  1. Avoid using any vinegar during your brewing process. There are actually plenty of online sources that recommend using vinegar in your starter liquid. I go over why this isn’t a good idea here. If you absolutely have to use vinegar, make sure it is completely pasteurized.
  2. Make sure you are using the right starter liquid. This will ensure the acidity of the brew is at the level where any outside parasites will find it hard to survive.
  3. Do not use vinegar cleaning products for you kombucha equipment. This is an easy way to contaminate your gear instead of actually cleaning it.

Although we definitely try, no one is perfect. If you’ve started growing your own little worms at home by mistake here are the steps you need to take to get rid of them completely.

I Have Vinegar Eels – Is There Anything I Can Do?

Unfortunately, there is no easy way to kill the eels without doing major damage to your scoby. It’s also not feasible to filter them out as they like to embed themselves into the scoby disc. Meaning the only way you’re going to get them out is by removing the actual scoby itself.

Therefore, your best option is to throw everything out and start from scratch.

I know this may be painful, but the only other alternative is to live with drinking them in your kombucha. Let’s be real, no-one wants that!

Once they have developed, they are notoriously hard to get rid of. Hopefully, you’ve been using one of your spare scobies from your scoby hotel. If not, you’re going to have to in search of a new mother.

When I say everything, I mean everything. With the exception of the brewing equipment (we’ll deal with that later.) Any kombucha that was brewing? Throw it out. Just the the starter liquid? Chuck it.

You want to remove any trace of the worms and any eggs they leave behind.

Time To Clean

Once you have gotten rid of any of the infected kombucha, it’s time to santize everything that comes in contact with your brew. Take every piece of equipment you use in your process and scrub it down with hot and soapy water.

If I were you, I would clean everything twice just to be sure you don’t miss any microscopic eggs. If you have any on hand, industrial-strength, food-safe cleaners will also do a great job. Just don’t use vinegar! There may be a chance you’ll ruin a second brew.

Be careful with any mason jars you may be using. There may be a chance of them cracking if you directly expose them to hot water. It’s better to place them in cool water and slowly heat them up to a boil.


I know it can be tempting to use raw apple cider vinegar as your starting liquid. It’s healthy and would provide an exciting flavor profile. But it’s just not worth the risk of vinegar eels. If you must, make sure the apple cider vinegar is completely pasteurized.

Remember, vingear eels are incredibly rare. It’s very unlikely you’ll wake up one day to a 1 gallon jar full of worms. It’s best to avoid vinegar and put them out of your mind completely.

Do you have any stories of finding vinegar eels in your brew? If so, be sure to share them in the comments below and how you handled them!

2 thoughts on “What Are Vingear Eels and How To Deal With Them”

  1. But if the idea of the backslop of vinegar is to introduce bacteria and yeasts to ferment my kombucha, what is the good of using pasteurised vinegar?

    • Good question. I would suggest to only use kombucha starter liquid to introduce bacteria and yeast into your ferment. I would avoid vinegar altogether – it’s unnecessary.


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