How Long Is Kombucha Good for After Opening—and How to Tell If It’s Still Safe to Drink

Kombucha is a fizzy, fermented tea known for its probiotic content and tangy flavor. But once you crack open that bottle, how long does it stay good? If you’re into organic living and mindful sipping, this question matters—not just for taste, but also for your health.

Let’s dive into how long kombucha lasts after opening, how to store it properly, and how to tell when it’s time to toss it.

What Happens When You Open Kombucha?

Once opened, kombucha begins to lose its fizz and can start to change in taste and bacterial balance. Kombucha is a living beverage, packed with natural cultures that react to air and temperature. As soon as oxygen hits the bottle, those microbial dynamics start shifting.

While kombucha doesn’t spoil the same way milk does, it can still degrade in quality—and in some cases, it can grow mold or unwanted bacteria if not stored properly.

So, How Long Is Kombucha Good for After Opening?

In general, kombucha is good for 5 to 7 days after opening if kept refrigerated.

However, there are a few key factors that influence this:

• Storage temperature
• Brand and brewing method
• Added ingredients (fruit, herbs, juice)
• How long it sat out at room temperature
• Whether it was poured into another container

Shelf Life Breakdown:

How to Store Kombucha After Opening

Proper storage is essential to preserving kombucha’s flavor, carbonation, and probiotics.

Follow These Guidelines:

• Always refrigerate after opening: Kombucha is best kept cold—ideally between 34°F to 38°F. This slows down fermentation and maintains fizz.
• Seal the cap tightly: Use the original cap or an airtight lid. Loose lids = loss of carbonation and exposure to contaminants.
• Avoid glass transfer unless necessary: Pouring kombucha into another container increases exposure to air and microbes. Stick with the original bottle.
• Keep it away from strong odors: Kombucha can absorb fridge smells like onions or garlic. Store it away from pungent foods.

Can You Drink Kombucha That’s Been Open for a Week?

Yes, if it’s been properly stored in the fridge, kombucha can still be safe to drink after a week. However, be prepared for:

• Less carbonation (it may be flat)
• A stronger, more vinegary taste
• Slightly different mouthfeel

Pro Tip: Give it a sniff and a small taste test. If it smells off, looks cloudy in a weird way, or tastes sour beyond tangy—it’s time to say goodbye.

Signs Your Kombucha Has Gone Bad

Most kombucha lovers know their brew well. But if you’re unsure, look for these warning signs:

Red Flags to Watch For:

• Mold – White, blue, green, or fuzzy spots floating on top. Discard immediately.
• Slimy texture – While natural strands are normal, excessively slimy textures may indicate contamination.
  
• Bad smell – Kombucha should smell sour-sweet. If it smells like rotten eggs or feet, it’s a no-go.
• Odd taste – Too sour, bitter, or even metallic? Don’t risk it.

Is Flat Kombucha Still Good?

Yes, flat kombucha (meaning it’s lost its fizz) can still be safe and drinkable, but it may not be as enjoyable. The fizz comes from natural carbonation created during fermentation. Over time, especially after opening, that carbonation can fade.

If you’re drinking kombucha for gut health rather than taste, flat kombucha might still deliver beneficial probiotics—just in smaller amounts.

How to Make Opened Kombucha Last Longer

Want to extend your kombucha’s lifespan post-opening? Use these tricks:

• Shake gently before sealing – This redistributes sediment and keeps probiotics more evenly spread (but never shake vigorously—it’s fizzy!).
• Use a vacuum sealer cap – These are available for kombucha and wine bottles to help keep the fizz.
• Keep it cold at all times – Even a short time at room temp can increase fermentation and shorten shelf life.

Is Homemade Kombucha Different?

Yes, homemade kombucha is different from store-bought varieties in a few key ways. It typically contains more active cultures, undergoes less filtration and pasteurization, and doesn’t include preservatives or stabilizers. These qualities make it more potent but also more perishable. 

Because of its freshness and strong probiotic content, many people wonder, “When is the best time to drink kombucha?” If you’ve made it at home, drinking it in the morning or before meals can help you get the most digestive benefits. Just be sure to refrigerate it and consume it within 3–5 days of opening, especially if cleanliness during brewing wasn’t ideal.

Can You Get Sick From Drinking Old Kombucha?

It’s rare, but yes—it’s possible. Drinking kombucha that has gone bad can cause:

• Stomach upset
• Nausea
• Vomiting
• Diarrhea

People with compromised immune systems, pregnant individuals, or those sensitive to bacteria should be especially cautious with old or homemade kombucha.

How to Tell if Kombucha Is Still Safe to Drink

Here’s a quick checklist before sipping that half-finished bottle:

• Stored in the fridge
• No mold or floating debris
• Smells slightly tangy, not foul
• Taste is sharp but not bitter or “off”
• Was opened within the last 5–7 days

If you answer “yes” to all of the above, you’re probably good to go!

Bonus: What to Do With Leftover Kombucha

Have an opened bottle you don’t want to waste but don’t feel like drinking? Try these clever ideas:

• Add to smoothies for a probiotic punch
• Use in salad dressings in place of vinegar
• Water your plants (diluted, and only if sugar-free)
• Create a kombucha vinegar by letting it ferment further (like apple cider vinegar) 

The Bottom Line: When in Doubt, Throw It Out

While kombucha is a naturally fermented and acidic beverage—meaning it’s more stable than many drinks—it’s still important to treat it like a fresh product. If something seems off, trust your senses.

Remember:

• Refrigerate opened kombucha right away
• Drink it within 5 to 7 days
• Look for mold, smell, and taste as safety checks
• When in doubt, don’t risk it

Kombucha is best enjoyed fresh and fizzy. So open it, sip mindfully, and drink it within a few days to get the most benefits.