Does Carbonated Water Expire? Shelf Life & Facts Inside

Ever found a bottle of carbonated water sitting in the back of your fridge and wondered, “Is this still safe to drink?” You’re not alone. With more people choosing sparkling drinks over sugary sodas, it’s a common question: does carbonated water expire?

While it may seem like water should last forever, carbonated water is a bit different. The bubbles, flavor, and even the packaging play a role in how long it stays fresh and fizzy. Whether you’re a casual drinker or a sparkling water addict, knowing how long carbonated water lasts can save you from a flat and flavorless disappointment — or worse, a potential health risk.

In this post, we’re diving deep into shelf life, signs of spoilage, storage tips, and everything else you need to know.

Does Carbonated Water Expire?

Yes — carbonated water does expire, but it’s not always a hard cutoff like spoiled milk or moldy bread. When we say it “expires,” we’re mostly talking about a decline in quality, not safety — at least when the bottle or can remains unopened and properly stored.

Most brands print a “Best By” or “Use By” date on their products. This date is not an exact expiration but more of a recommendation for when the drink will taste its best — fresh, fizzy, and crisp. After that date, the carbonation starts to fade, and the flavor (especially in flavored versions) may become dull or slightly off.

It’s important to note that while expired carbonated water won’t typically make you sick, it might taste flat or stale. However, damaged packaging or improper storage can lead to contamination — which can be a health risk. So, it’s not just about the date — it’s also about condition.

What Happens to Carbonated Water Over Time?

Over time, carbonated water changes — even if the bottle is sealed. The most noticeable shift? It loses its fizz.

That pleasant bubbling effect comes from carbon dioxide (CO₂) gas. In a sealed container, the gas stays dissolved in the water under pressure. But as time passes, tiny amounts of gas can still escape. This leads to flat-tasting water, especially if the bottle is opened and not tightly resealed.

Besides losing its carbonation, the flavor might become dull, especially in flavored sparkling waters. If there are added ingredients — like natural flavors, sweeteners, or fruit extracts — they may break down or taste slightly different over time.

Chemically, the water itself doesn’t “go bad.” But the change in taste and texture can make it unappealing. That’s why knowing the shelf life is helpful — not just for safety, but also for enjoying the drink the way it’s meant to be.

Shelf Life of Carbonated Water

So, how long does carbonated water actually last?

Unopened Carbonated Water

When stored properly, unopened carbonated water can last anywhere from 12 to 24 months past the production date. This depends on the brand, packaging, and whether it’s flavored.

• Cans usually have a longer shelf life than plastic bottles, because they’re airtight and protect against light.
• Glass bottles are good too, but if not sealed tightly or stored upright, they may lose fizz faster.

Opened Carbonated Water

Once opened, the countdown begins. Even with a cap, carbonation starts escaping. Here’s what to expect:

• 24 to 48 hours in the fridge: Still fizzy, especially if tightly resealed.
• After 3 days: Mostly flat, unless stored in a pressure-saving container.

Flavored vs. Unflavored

Flavored carbonated water may have a shorter shelf life due to added ingredients. These can degrade or separate, affecting both the look and taste.

Bottom line: check the packaging date and trust your senses — if it tastes flat or smells off, it’s probably past its prime.

How to Tell If Carbonated Water Has Gone Bad

Wondering if your bubbly drink has gone bad? Here are a few easy signs:

1. No Fizz

This is the biggest clue. If there’s no “pop” when opening, or no bubbles in the glass, the carbonation is likely gone.

2. Strange Smell

Pure carbonated water shouldn’t smell like anything. If it has a sour, musty, or off odor, especially in flavored versions, it’s best not to drink it.

3. Cloudiness or Sediment

The water should be clear. Cloudy water, floating particles, or a hazy look might mean the drink is contaminated or ingredients have broken down.

4. Leaking or Damaged Packaging

If the bottle or can is swollen, leaking, or rusted, don’t risk it. That could indicate bacterial activity or broken seals.

Trust your senses — they’re a better judge than a printed date sometimes.

Is It Safe to Drink Expired Carbonated Water?

In most cases, yes — as long as the container is unopened and undamaged. The water might be flat, but it won’t harm you.

However, there are exceptions:

• Flavored versions: Expired ingredients could taste weird or spoil faster.
• Damaged bottles: If a bottle is cracked or bulging, bacteria could sneak in.
• Expired and poorly stored: Heat and sunlight speed up breakdown, making the water less safe over time.

It’s always smart to check the date and the condition of the package. If in doubt, toss it out.

How to Store Carbonated Water for Maximum Freshness

Proper storage can stretch your carbonated water’s shelf life and keep the fizz strong.

Before Opening

• Store in a cool, dry place — pantry or cupboard works well.
• Keep bottles or cans upright to prevent leaks and preserve seals.
• Avoid sunlight and heat, which can degrade plastic and affect carbonation.

After Opening

• Refrigerate immediately.
• Seal tightly with the original cap or a carbonation-saving cap.
• Drink within 2–3 days for the best experience.

Some people even use soda siphons or carbonation machines to re-carbonate leftover water — handy if you’re a fizz fan!

Carbonated Water vs Soda: Does One Expire Faster?

Carbonated water and soda both use CO₂ to create fizz, but they don’t age the same.

Soda

• Contains sugar, preservatives, and acids.
• These ingredients can spoil or change taste faster.
• After expiration, soda may taste metallic, overly sweet, or flat.

Carbonated Water

• Plain varieties last longer due to fewer ingredients.
• Flavored ones fall somewhere in the middle — not as stable as plain, but not as sensitive as soda.

So yes, soda may expire faster, especially once opened. Plain sparkling water is usually the most stable option.

Also Read: Does Sparkling Water Expire? Shocking Facts You Must Know

Frequently Asked Questions (FAQs)

Can you drink expired carbonated water?

Yes — if it’s unopened and stored well, it’s usually safe, just flat.

How long does it stay fizzy after opening?

Typically 1–3 days if sealed and refrigerated.

What happens if you drink old sparkling water?

You might not enjoy the taste, but in most cases, it won’t hurt you.

Does flavored sparkling water expire faster?

Yes. Added ingredients break down quicker than plain water.

Is the expiration date on carbonated water strict?

Not really — it’s more of a quality guideline than a safety warning.

Conclusion

So, does carbonated water expire? Yes — but not in a way that’s usually dangerous. Over time, the fizz fades, and the flavor may go flat. But if your bottle is sealed, stored properly, and not past its prime by years, it’s likely safe to drink.

Understanding shelf life, signs of spoilage, and how to store it can help you enjoy every last bubble. And next time you find an old bottle in the fridge, you’ll know exactly what to do.