Can Kombucha Go Bad?

“You’re not getting enough probiotics” is what almost every site health-related site tells you at some point. And kombucha often comes up as a convenient solution. So you buy a bottle or two to give it a shot, and maybe you even make it a regular thing. But sooner or later you find yourself with old kombucha or notice there’s a gelly floating thing in the bottle, and you’re not quite sure what to do.

Telling whether kombucha is bad isn’t super straightforward, and not all manufacturers specify that sort of information on the labels or even their websites. The shelf life also often shows up at a date on the label without any further context. And that’s too bad because many people throw out perfectly good kombucha because of that lack of info.

This article is here to cover that gap. In it, we talk about possible signs of spoilage of kombucha, its storage and shelf life. If you’re a kombucha drinker who lives and dies by the “best-by” date, this article is definitely for you. Continue reading.

Homemade kombucha
(credit: Klara Avsenik )

Can Kombucha Go Bad? How To Tell If Kombucha Is Bad?

Telling if kombucha is off is a bit tricky. It’s a fermented product and therefore very acidic. That, in short, means any microorganism that isn’t already there has a hard time living and growing in such an environment. Because of that, the beverage lasts a long time and doesn’t spoil easily. However, in some rare cases, things may go south.

The first and most obvious sign of spoilage is the presence of mold. It’s super rare and happens mostly with homemade kombucha or an old one that developed its own baby SCOBY (more on that below) on top, and mold started growing on it. If there’s mold, throw it out.

The second option is that the kombucha turns vinegary in taste ([NE]) and you don’t find it good enough to drink anymore. If that’s the case, instead of throwing it out, you can use it as a vinegar substitute. This is a natural result of fermentation and happens to kombucha that’s stored for months in the fridge or opened at room temperature for a couple of weeks or so.

If your kombucha starts to smell off after a few days of opening, and you tend to drink directly from the bottle, switch to using glasses. There’s most likely nothing wrong with the liquid, but the bacteria from your mouth have contaminated the neck of the bottle, and that’s what’s causing the smell. If you’re always using a glass and your kombucha stinks, discard it.

That’s about it when it comes to signs of bad kombucha. But there are also at least a few things people find concerning and which are perfectly normal for the probiotic drink. Here they are:

  • Fizz or lack of it. Kombucha is a living thing, and the presence or absence of fizz depends on the batch, storage conditions and how long it’s stored. Even if you always buy the same brand and store it the same way, the effervescence will vary ([GTS][NE]).
  • Floaties in the bottle. The gel-like thing or a bunch of strands forming in the liquid is a baby SCOBY (Symbiotic Colony Of Bacteria and Yeast). A scoby is used in the process of making kombucha, and it can form on its own over time even if it was filtered out before bottling. Think of it like the mother forming in vinegar. It’s safe to consume it, but if you find it gross, just filter it out ([CK][GTS][NE]).
  • Sediment. Some sediment on the bottom is nothing unusual. If you want to mix it up, tilt the bottle gently left and right. Do not shake it, or it might explode like champagne ([GTS][RK][NE]).

Now that you know all about what is and what isn’t spoiled kombucha, let’s talk about its shelf life.

Prepared homemade kombucha
(credit: Klara Avsenik )

How Long Does Kombucha Last?

The answer to this question depends on whom do you ask, and usually varies between a couple of months, to possibly a year ([CK]). The industry standard seems to be about 6 months of bottling ([CK][RK]). And if you want to keep things super simple, you can just discard the kombucha that’s passed the date on the label. But as I already mentioned in the intro, that would be wasteful in my opinion.

As you already know, kombucha doesn’t readily go bad, so it’s not like it will magically go off after a week or two after the date on the label. That date is merely an estimate of how long the quality should be good enough for drinking. And since the fermentation process is going on all the time, like in unpasteurized sauerkraut, the change is slow and gradual. So it’s not like one day it will be perfectly fine and turn awful the next morning.

But at a certain point, you will notice that the kombucha no longer hits the spot, and that’s when it’s time to either discard it or use it for other purposes ([NE]). And that obviously depends on your personal preferences, so there are no hard and fast rules if that happens near the best-by date, or a couple of months later. And it varies between batches, so even if you’re loyal to a single brand, this period will vary. As long as the kombucha doesn’t show any signs of spoilage covered earlier, drink a tiny amount and decide if you find it good enough or not. Chances are you will enjoy it for at least weeks beyond the “expiration” date.

And speaking of shelf life, the way you store this beverage also affects how long you can keep it around.

How To Store Kombucha?

When it comes to an unopened bottle, the recommended storage method varies between producers. Some say you can keep it at room temperature ([CK]), while other manufacturers show a strong preference for refrigeration ([GTS][RK][NE]). When in doubt, keep in in the fridge. Of course, if you leave it out for a day or two, it won’t turn vinegary right away, but it definitely won’t keep good quality for as long as if it’d sit in the fridge all the time.

Once you open the bottle, its place is in the refrigerator. The cold temperature keeps the fermentation in check, so it doesn’t turn too acidic too fast. So if you like your kombucha on the less acidic side, make sure it’s refrigerated at all times, the same way you’d care for dairy products like kefir or yogurt.

When it comes to how to store the bottles, make sure you always keep them upright and not on their side ([GTS]). Otherwise, you might end up needing to wash your fridge after some of the liquid has escaped the bottle.

In a Nutshell

  • Kombucha doesn’t go off quickly, but if there’s mold, it tastes like vinegar or smells off, it’s time for it to go.
  • The gel-like substance forming in the bottle is safe for consumption and doesn’t make the liquid bad or spoiled. If you find it gross, filter it out.
  • This probiotic drink is a living thing, so its flavor, amount of bubbles, and how long it tastes good differs between batches. Even if you buy it only from one producer, the kombucha you get will be slightly different every time.
  • Store kombucha refrigerated at all times unless the label says otherwise.
  • If it doesn’t show any signs of spoilage, it’s most likely okay to drink, even if it’s a couple of months after the date on the label.