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‘I Forgot To Refrigerate My Kombucha!’ Now What?: Everything To Know About Kombucha Going Bad

Updated: Feb 10, 2021



I'm guilty of saying the above line way too many times. But having done my research, I also understand the implications of leaving my kombucha bottle out of the refrigerator for too long a time.


If you’ve left your kombucha outside the refrigerator for a few hours or a couple of days, that won’t be an issue for most. The main problem arises due to fermentation that occurs within your kombucha bottle if left outside at room temperature. So if left for short periods of time it will barely alter its taste profile.


Having said that, how much your kombucha ferments and how it affects your experience of drinking kombucha depends on a bunch of factors.


For starters, Yes, your kombucha should always be refrigerated. Kombucha, when made the good way, is unpasteurized and raw Unpasteurized implies that it yet has all the good bacteria for our gut and hence if left outside the fridge will continue to ferment at room temperature.


Why Does It Matter If I Leave My Kombucha Outside The Refrigerator?


So we all obviously know that kombucha is a fermented beverage, right? As with any fermentation, in kombucha fermentation too, temperature makes all the difference. It literally can take half the time fermenting kombucha in India as against fermenting kombucha in Canada. Kombucha is generally (and, ideally) fermented between 20 and 30 degrees celsius.


The time and temperature of fermentation decide the taste profile, carbonation, caffeine content, alcohol content of the final kombucha.

Once kombucha is brewed and ready to drink (you’ve tasted it and set your heart on the flavor profile and carbonation level it has achieved), you would, of course, want it to remain the same


Understanding this will throw some light on what happens to kombucha room temperature as against stored in the refrigerator.


What Different Happens To My Kombucha When It’s Stored Out Of The Refrigerator?


So as I was explaining above, at room temperature, some changes are definitely going to occur.


  1. As in any fermentation, the live bacteria feed off the sugar. So if kombucha is left out, the live bacteria are going to eat the sugar at room temperature

  2. Caffeine is also consumed by the bacteria during the fermentation process. The final kombucha has around 1/3rd the caffeine level of the tea used to brew that kombucha. So the longer the kombucha is left out, the more the bacteria are going to reduce the caffeine

  3. Alcohol is a by-product of any fermentation. Kombucha contains around 0.5% alcohol, however, it’s yet classified as a nonalcoholic beverage. This by-product of alcohol also marginally increases the longer it’s left out at room temperature

  4. A majority of the calories of kombucha come from sugar. So if the sugar reduces if kept out, so will the calories

  5. Carbonation in kombucha occurs when brewers put their kombucha through a second fermentation. In this stage of the kombucha making princess, kombucha along with some added flavors are put in an airtight bottle to build up carbonation. The same happens at room temperature when a packaged airtight bottle is left out, the carbonation will increase

  6. For all practical purposes, this is why you should not leave your kombucha out for long. Beyond a certain point (maybe like 2 days), the kombucha will come too vinegary and unpalatable for you.

Caveat: All of the above is purely educational. It might weirdly seem a compelling reason to leave your kombucha out. But you must understand, kombucha is brewed and fermented till a certain point to deliver great taste along with a bunch of health benefits.


So even if the sugar content will reduce if left for long at room temperature, the taste is going to be just too unpalatable for you to enjoy your Booch!


Also, all the above changes will take place the longer the kombucha is stored in the refrigerator, but just at a MUCH MUCH slower rate and thus maintaining your desired taste profile for much longer.


What Is The Most Ideal Way To Store Kombucha?

Yeah, I am sure you’ve got it by now. The most ideal place to store your ready kombucha is in a refrigerator between 0 to 6 degrees celsius, whether it has been home-brewed or commercially purchased.


At this temperature, the bacteria and yeast go into a state of dormancy (yeah, they kinda pass out) and without those little buggers, the pace of fermentation also drastically reduces. This leaves the taste profile, sugar content, etc. vastly unaltered for long periods of time.


Does Kombucha Have Any Preservatives?



Good Question. Kombucha can be considered self -preservatory and hence does not require any preservatives. To add some context, traditionally, a lot of foods were fermented for the purpose of preservation and not for the numerous health benefits that we consume them for today.


During the process of fermentation, bacteria feed on starch and sugar to produce healthy organic acids and also reduce the pH of the brew. For example, kombucha will always have a pH of <4.


At this low pH, it is almost impossible for pathogens to inhibit, survive, and contaminate the kombucha, which is why governments all around the world allow fermented foods to be sold without preservatives.


Wait, So Then How Long Does Kombucha Actually Last For?

Yup, now we’re getting to the real stuff. Technically, for very very long.

There is no specific time period after which it goes bad. It isn’t like dairy products, wherein overnight your fresh cream or cottage cheese goes sour. So all I can give you are guidelines which will help you understand if you can have your kombucha whether it’s after 3 months or 6 months.


If left in the refrigerator, your bottle of kombucha should be good for you indefinitely, as long as its taste doesn’t bother you.


However, after a really long period of time (like 6 months or so, you might (although very unlikely) see your kombucha flat with no carbonation (carbonation generally increases with time) or having a yeasty or foul smell (a vinegary smell is expected, then that would be indicative to make a sad face and throw it down the drain.


If left at room temperature, your bottle of kombucha is likely to get too sour to consume within 7-10 days. It also (unsurprisingly) depends on what the room temperature is. The hotter it is outside the faster it is going to ferment and get sour. Although it will get sour and fizzy af, it doesn’t make it unsafe for consumption, unless it is weirdly flat and/or has a foul smell or mold growth on the surface. If you see a SCOBY, don’t worry, that’s completely safe. Confused about how to differentiate them? Check this resource out!


If you’ve touched your mouth to your bottle of kombucha (Indians reading, #jhoota), then you should ideally consume it within a week’s time. This is because our saliva has a spew of its own strong bacteria that might contaminate the kombucha if left for long periods of time.


So Then Why Do Commercial Kombucha Bottles Mention An Expiration Of 60/90 Days?


Short Answer: They legally and morally have to. It’s also more of a best before than an expiration. Any kombucha brand makes their kombucha match some taste profile that they think their consumers are going to absolutely love. Now understanding that after 60/90 days, this taste might very well be different than what a consumer expects, it’s quite intuitive why a kombucha manufacturer is going to not want its consumers to drink their Booch after the taste has already changed so radically than what they intended it to be.


The Bottom Line: How Do I Know If It’s Yet Safe To Consume?

It comes down to your palate. Look, it’s very unlikely that kombucha goes ‘bad’ ever. As fermentation continues, the taste will change and after a point, you just won’t like it anymore. So, if you have a bottle that has passed the best before date, then please don’t throw it away blindly! Open and taste it, if it all seems good to you, you’re good to go!


P.S. – Sometimes I actually enjoy drinking really old aged kombucha. Although it doesn’t take as you’d expect, it gets this beer-y taste that you might just love. In one incident, I left The Culture Ko.s pineapple kombucha in my fridge for like 6 months, and oh man, it tastes so good and had some great fizz to it too!



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