Here's How Long Kombucha Stays Good After Opening

Kombucha has emerged as a super-beverage in the last five years, having been linked, by virtue of its composition (it's basically tea that's been fermented with a mixture of bacteria and yeast called SCOBY), to healthful digestion, immune system support, weight loss, lower blood pressure, and improved energy levels. With its popularity growing by leaps and bounds year over year (some fans even brew kombucha at home), kombucha drinkers might be wondering how long a bottle of the store-bought type stays good after it's been opened.

You have about one week to drink that opened bottle of kombucha before it might start to turn, so you can enjoy it at a moderate clip — no need to chug the entire thing in one day (in fact, you should sip kombucha through a straw for the best results). Kombucha keeps best in the fridge, opened or not, so give it a place on the bottom shelf, near the back, to keep it at its coldest (so that the fermentation process – which is still active — is slowed). That said, if you want your 'booch to regain some of the carbonation it lost when it was opened, you can leave it to ferment at room temperature for one to two days, then return it to your fridge.

Steady, reliable refrigeration is a modern marvel, and it certainly has a marvelous effect on kombucha. You see, the bacteria and yeast that ferment to give the drink its fizzy effervescence and distinctive tang, are actually alive the entire time – when it's in the bottle, as you drink it, and even after you replace the cap on a half-drank container. Refrigeration helps keep them alive, though at a more stagnant rate than if they were left out in warmer temps.

Refrigeration of kombucha is also required because those live and active cultures can get a little rowdy when kept at room temperature. They can build the fizz and carbonation in your kombucha until the top actually explodes off the bottle! So it's okay to leave the kombucha out for a few days, but you are definitely tempting fate — and a huge mess — if you leave it unrefrigerated for too long. (You can, however, burp your kombucha every few days by opening the lid just a bit, not all the way, and releasing some of the pressure.)

Despite kombucha's penchant for only getting fizzier as it ages, it can go bad, and the one sure sign is that you see mold floating around at the surface. This may appear in a multitude of colors, including your typical green and blue, but also black or even white. Unfortunately, because it's a liquid, you cannot simply remove the mold (as you might do with some cheeses) and drink the beverage as usual; that fuzzy stuff you see on the top is indicative of spores and roots all throughout the bottle. If you drink moldy kombucha (for whatever reason), depending on what kind of mold you've consumed, prepare yourself for some stomach upset and bloating.

However, there are also a few symptoms that may seem suspicious, but actually aren't signs that your kombucha has gone bad. You might notice little threads floating around in your beverage; those are actually yeast strands, and they're totally normal and not cause for concern. There is also the flavor; abnormally sour or vinegar-tasting kombucha isn't necessarily harmful (the liquid within is ultra-fermented), but you might be hard-pressed to get it all down.