What Happens If Kombucha Ferments For Too Long?


Kombucha is becoming a very popular drink, which is understandable as it is very tasty with the added benefit of being really good for you, especially for your gut health. Unfortunately, there are some cases where you are trying to make this delicious drink, but you leave it to ferment a bit longer than you should have. What happens if kombucha ferments for too long?

Kombucha that is fermented for too long will become very sour, and eventually, if left for even longer, it will turn into kombucha vinegar. This sour Kombucha and kombucha vinegar is still safe for human consumption and can be used in recipes as a substitute for normal vinegar.

So, Kombucha can over-ferment and turn into vinegar if left for long enough, but is there a way to slow this process down or prevent it entirely? And what exactly can you use this kombucha vinegar for? Some of the uses for kombucha vinegar may just surprise you. Let us have a look. 

How Does Kombucha Get Over-Fermented?

Kombucha can be a very refreshing and healthy drink, especially when it is fermented just right. However, fermenting Kombucha well does require a bit of finesse and some good timing which does take some practice, and even a kombucha fermenting expert can get it wrong at times.

Fermenting Kombucha into a tasty drink should only take about one to two weeks. After this ideal fermenting time is up, the kombucha liquid is separated from the Kombucha Scoby, and then it is bottled. 

When You Forget About Your Fermenting Kombucha

Sometimes this ideal fermenting time can be extended for far too long, though, either by forgetting the fermenting Kombucha or by your life just getting so busy that you do not have time to check your fermenting Kombucha. This extended fermenting time can cause the Scoby to get too active and cause over-fermentation to occur. 

When You Ferment Your Kombucha at a Higher Temperature

If you do not watch the temperature at which you are fermenting your kombucha drink, too, and the temperature is not kept at a constant temperature, and it goes too high, then this could cause the Kombucha to ferment a lot faster than you were expecting it to. If you are not expecting this fast ferment, then it is easy to over-ferment your Kombucha as you will not check it accordingly.

What Happens To An Over-Fermented Kombucha?

Over-fermenting Kombucha can happen if you do not keep a close eye on your Kombucha, and this over-fermentation will cause your kombucha drink to turn into kombucha vinegar

However, this process where your Kombucha turns into kombucha vinegar can take some time, and there is a stage during this where you can still drink the Kombucha as a drink if you can handle the sour taste, that is.

NOTE: If you can handle a sour taste, then your Kombucha will probably still be drinkable after two and a half weeks of fermentation. However, the closer you get to the third week mark, the closer your Kombucha will be to becoming kombucha vinegar, which is defiantly not suitable for drinking. 

Do not throw away your kombucha vinegar, though, as there are many different and tasty ways you can use this kombucha vinegar; some of them may surprise you.

We will go through some of the ways you can use this kombucha vinegar later on in this article. 

How To Tell If Your Kombucha Is Over-Fermented

Kombucha that has been fermented just right is a very tasty drink and has some good health benefits to it as well. It may be somewhat difficult for you to tell whether your Kombucha has fermented too long or if it is still drinkable. 

People also have different preferences when it comes to taste, so a kombucha that is too sour for one person may be just right for another person. This means that you will need to experiment with fermentation times to get the right fermentation level that suits your taste preference.

That being said, your preference may vary from our discussion here. First, we need to know what Kombucha that has been fermented correctly tastes like before we try and see if it’s fermented too far. Let us go through what a correctly fermented kombucha drink should taste, smell and look like. 

Kombucha That Is Fermented Correctly

In a kombucha drink that has been fermented correctly and for the correct amount of time, the Kombucha’s taste will start off with a sweet taste that then leaves a slight vinegar after taste. This is normal and indicates that the Kombucha is ready to be enjoyed as a tasty drink. 

In Kombucha that has been fermented for a little bit too long, the vinegar after taste will be a bit stronger, but this should still be drinkable if you like slightly sour things. 

Correctly fermented Kombucha will have a bit of a sweet vinegary aroma to it as the fermentation process progresses.

This vinegary smell is caused by the good bacteria in the Kombucha creating beneficial acids in the liquid that help with the fermentation. 

These acids are mainly acetic, glucuronic, and gluconic acids, with acetic being the most noticeable one as this is what causes the Kombucha to have a vinegary smell as acetic is the same acid that is in vinegar. The longer you leave your Kombucha drink to ferment, the more acids will build up in the Kombucha, causing a stronger vinegar smell. 

As kombucha ferments, the Kombucha Scoby will feed on the tannin in the tea that you put in it to make your kombucha drink, and this tannin is what gives Kombucha its color. So, when the kombucha drink is ready to be bottled and enjoyed, the kombucha liquid will be lighter in color compared to when it first started to ferment.

3 Ways To Check For Kombucha Over-Fermentation

So, how can can you tell if your Kombucha is over-fermented? There are 3 ways to find out:

  1. Smell – First, you should smell the fermented Kombucha. If the Kombucha is over-fermented, it will have a very strong vinegar smell as the acids in the Kombucha have built up to a very high level.

    This vinegar smell will be very strong and can be quite pungent, and the slightly sweet smell that is in the Kombucha that is ready to drink will be gone. 
  2. Color – Have a look at the color of the fermented Kombucha; as we mentioned, the Kombucha will gradually get lighter in color as it ferments as the Scoby eats the tannin in the tea.

    So, when Kombucha is over-fermented, the color will be extremely light. It will still have some color to it, but it will be more of a tint than a proper solid color. 
  3. Taste – The Kombucha might have an extremely vinegary taste and is really sour and may even be unpalatable for some people, without the pleasant, sweet taste of normal fermented Kombucha.

    The Kombucha will taste this way as there is a high build-up of acid that will overtake the taste of the tea that you used to ferment the Kombucha with.

All of these signs put together are a good indication that the Kombucha is over-fermented and may have turned into kombucha vinegar.

TIP: This kombucha vinegar is still safe for human consumption; however, it will definitely be too sour to just be a refreshing kombucha drink. But do not throw this vinegar away as you can use it in many different ways, and you can get quite creative with it. 

5 Alternative Uses for Over-Fermented Kombucha

Thankfully, there are loads of ways in which you can use your Kombucha that is over-fermented or that has turned into kombucha vinegar. These methods range from cooking to immune-boosting drinks and can even be used in your daily skin routine for brighter skin. Let us go through some of these uses.

1. Fire Cider

You can use over-fermented Kombucha to make Fire Cider, which is an immune-boosting drink. To make Fire Cider, you mix your over-fermented Kombucha with ginger, garlic, horseradish, and onions (you do not have to use all of them together) and then leave them to infuse together for an hour or two in the fridge, then you pour it through a sifter. 

Once you have the kombucha liquid separated from the solids, you can then mix in a bit of honey to add in some sweetness as well as adding some more immune boosters from the honey itself. Then chill the drink in the fridge and take a shot of it every morning to help boost your immune system.

If you enjoy eating salads, then you can try using your over-fermented Kombucha as a salad dressing, you can use it as is, or you can incorporate it into a salad dressing recipe as a substitute for the vinegar in the recipe. 

2. Salad Dressing

Adding the over-fermented Kombucha to your salad dressings will give your salad dressings the extra advantage of being gut healthy. This means that the Kombucha will help introduce good bacteria into your stomach that will help aid in digestion.

Salad dressings are usually a mixture of spices, oil, and vinegar. Using the vinegar from your over-fermented kombucha will add a dose of probiotics and make your salad even healthier!

3. Organic Hair Rise

Another great use for over-fermented Kombucha is to use it as a natural and organic hair rinse. The extra levels of acetic acid in the Kombucha helps your hair in many different ways; it can remove build-up, clarify your hair, reduce scalp dryness or itching, helps to re-balance your hair’s pH reduces frizz and breakage as well as re-seals the hair cuticles. 

If you use Over-fermented Kombucha on your hair, your hair will absolutely love you for it. Your hair will be shiny, healthy, and clean, and you will not have to go and buy an expensive hair product to get the same results. You can use the Kombucha as a natural rinse once a week. 

4. Natural Make-Up Remover or Facial Toner

The acetic acid in the Kombucha has great anti-fungal and antimicrobial properties in it which makes it excellent in helping to clear up acne and other small infections. 

Acetic acid is also astringent, which helps it to give your skin a deep clean, and it can help remove impurities too. 

5. Starter Culture for More Kombucha

Fermented kombucha vinegar makes a great starter culture for your next batch of Kombucha, as well as a good Scoby hotel.

A Scoby hotel is a great place to store your extra Scoby that may develop from fermenting Kombucha. The kombucha vinegar will keep the excess Scoby healthy until you are ready to use it. 

These are just a few options of what you can use your over-fermented Kombucha for; you may even decide to create your own unique recipes, and the nice thing about Kombucha is that you can be quite creative with it and use it for many different things. So, get your creative juices flowing!

How To Prevent Kombucha From Over-Fermenting

Kombucha can over-ferment for a number of reasons, but there are a few ways that you can help prevent this over-fermentation from occurring. 

Keep An Eye On Your Kombucha

The first way you can help stop your Kombucha from over-fermenting is to keep an eye on how long you are fermenting it. As mentioned earlier, leaving your Kombucha to ferment for too long can make it sourer or even turn it into kombucha vinegar. 

There are some methods that you have at your disposal to help you not leave your fermenting Kombucha for too long. 

Shorten The Fermentation Period

You can reduce the number of days of fermentation for your Kombucha to ensure that it does not over-ferment, but depending on other variables, like the temperature you keep your Kombucha at, this may make your Kombucha under-fermented. 

Note: If you’re interested in speeding up fermentation time, here’s an article I wrote full of tips on how to speed things up without compromising on the quality and health benefits of your fermented food!

If you find that your Kombucha is over-fermenting because you forget about it, then you can set an alarm on your phone to remind you to check it at the same time every day, which will help you catch your Kombucha before it over-ferments.

Ferment In Lower Temperature

You can try to keep your Kombucha in a colder location to help stop it from over-fermenting, you can place it in a cooler part of your home, or you can place it in the fridge.

If you reside in a hot climate, you need to be aware that your Kombucha may ferment faster due to the heat, so calculate your days accordingly or try to keep your fermenting Kombucha in a colder environment, like a kitchen cabinet, and check it every day

TIP: If you put the Kombucha in the fridge, you do still need to check on your Kombucha regularly as you do not want the fermentation process to stop completely, which can happen if the Kombucha gets too cold for too long.

Do a Daily Taste Test

Another way to help stop your Kombucha from over-fermenting is to taste it on a daily basis; tasting your Kombucha not only helps you to know when it is ready and you should bottle it, but it also ensures that you get the flavor that you like in your Kombucha more easily.

This allows you to stop the fermentation of the Kombucha when it has reached the taste that you desire instead of it over-fermenting and becoming too sour for your liking. 

Reschedule Your Next Batch

If you become too busy to check on your Kombucha every day, then you may want to either hold off on making a batch of Kombucha until your life calms down a bit, allowing you the time to keep an eye on it.

Ask For Someone’s Help In Checking Your Kombucha

You can also have someone else who is knowledgeable in fermentation check on your Kombucha on a regular basis while you are busy with your schedule.

Don’t Be Sad About Your Over-Fermented Kombucha!

Kombucha can ferment for too long, which can turn it into kombucha vinegar or at least make it a bit too sour for most people’s tastes. This can be quite disappointing as you were looking forward to a nice batch of Kombucha to drink. 

However, there are many ways in which this sour Kombucha can still be used, so you can still get all the health benefits from it. Besides, this also allows you to get creative and have fun, as you come up with different recipes!

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