How Long Does Opened Kombucha Last?

Kombucha is a popular fermented drink touted for its many supposed health benefits, from promoting good gut bacteria that aid digestion to improving immune function and lowering cholesterol. However, there's a lot you need to know before you drink kombucha, especially if you're moving past the listed "best by" date on the bottle or drinking the homemade variety. While the light, fizzy, and slightly acidic taste can vary based on how long the kombucha has been bottled, a sourer flavor profile can also signify spoilage. 

Canned and bottled kombucha usually maintains freshness for six to eight months, but once opened, it's best consumed within one week. Several variables come into play once kombucha is opened; not only does the temperature need to be cold enough to keep the probiotic cultures alive, but when kombucha is exposed to air, it starts to lose carbonation and nutrients.

Understandably, kombucha will be the freshest immediately after opening. However, this doesn't necessarily mean the beverage is unsafe to drink beyond that point. Bottled kombucha that can be tightly resealed after opening can stay carbonated in the fridge for over a week. Inspect the liquid regularly and, if it starts to look different – especially cloudy or moldy — it should be thrown out.

Interestingly, as long as kombucha's natural cultures remain alive, the good bacteria can prevent the growth of bad bacteria or mold, technically meaning it's safe for consumption. However, leaving resealed kombucha in your fridge for weeks or months will cause those delicate flavors to dissipate, leaving a strong taste of vinegar, which most do not find enjoyable. 

Most store-bought kombucha brands are on the pricier side, with some being over $4 for just 16 ounces, and there are a lot of expenses associated with homemade kombucha. Therefore, it's understandable that throwing out a perfectly good kombucha simply because it has been opened would be a frustrating thought.

It's important to know, however, that the bacteria in your saliva can increase contamination risks in your kombucha over time, so if you aren't planning on consuming the entire bottle in one sitting, it's best to pour the beverage into a separate glass. This will prevent the bottle from touching your mouth and stop any backwash from getting into the kombucha. Ultimately, one week in the fridge is a good rule of thumb for opened kombucha to maintain its flavor, but the timeline is largely up to personal taste.