Is expired sparkling water bad for you?

Quick Answers

Sparkling water that has expired is generally still safe to consume, though the taste and carbonation may degrade over time. Drinking flat or expired sparkling water is not harmful, though it may taste unpleasant. Properly stored, unopened sparkling water can remain good for 9-12 months past the expiration date. Opened sparkling water only lasts 1-2 days after opening before going flat.

What happens when sparkling water expires?

The main thing that happens when sparkling water expires is that it loses carbonation and goes flat. The dissolved CO2 gas escapes the liquid over time, especially if the bottle has been opened. Flat sparkling water may taste stale or dull. The flavors also can degrade and taste off. However, expired sparkling water is still safe to drink with no health risks. The expiry dates refer to peak quality rather than safety.

Chemical composition

Sparkling water is made by infusing water with carbon dioxide gas under pressure. This produces carbonic acid, which gives the water its bubbly, acidic taste. However, the carbonic acid decomposes over time as the CO2 escapes the liquid. This leaves plain water behind. Expired sparkling water may contain trace amounts of carbonic acid left over, but not enough to be noticeable. The main minerals like sodium, magnesium, and potassium remain after expiration. The water does not go bad or spoil long after the bubbles are gone.


Some sparkling waters contain preservatives like potassium sorbate to help maintain carbonation and freshness for longer. However, these preservatives cannot prevent expiration indefinitely as the CO2 gas still escapes over time. At most, preservatives may extend the lifespan of sparkling water by a few months past its expiry date. Once opened, sparkling water only lasts 1-2 days before going flat, even with preservatives.


For flavored sparkling waters, the added natural flavors or essences can degrade over time after expiration. This can give the sparkling water a dull, muted taste rather than the bright flavors when freshly made. The flavors don’t necessarily go bad or become unsafe to ingest, but the taste profile changes due to the natural breakdown of the flavor molecules over months. Flavored sparkling water may lose its appeal faster than plain carbonated water.

Does expired sparkling water go bad?

No, sparkling water does not go bad in the sense of being unsafe to drink when expired. As a carbonated beverage, sparkling water has an extended shelf life. The water itself does not spoil or become contaminated over time. Unopened, commercially packaged sparkling water can remain fresh and retain carbonation for up to a year past its printed expiry date if properly stored.

Safety of ingredients

The ingredients in sparkling water including carbonated water, natural flavors, and preservatives like potassium sorbate do not spoil or become hazardous over time. Potassium sorbate may form trace amounts of acrylamide over very long storage periods (years), but well below dangerous levels. For all intents and purposes, the ingredients remain safe to consume long after the sparkling water expires.

No microbial growth

The carbonation, acidic pH, and lack of nutrients in sparkling water prevent microbial growth. Harmful pathogens like bacteria, mold, and fungi cannot grow in sparkling water, so expired product does not pose contamination or foodborne illness risks. The sealed bottles also prevent external microbial entry. Sparkling water is shelf-stable and does not require refrigeration to stay safe.

Comparison to soda

Unlike sparkling water, soda can actually go bad when expired due to its sugar content. Over time, the sugars can oxidize and degrade, giving soda a metallic taste. Soda can also grow mold if left for too long. However, sparkling waters contain no added sugars that can spoil. The only sweeteners are non-nutritive ones like stevia or sucralose that stay stable over time in the finished beverage.

How long does unopened sparkling water last after expiry date?

If kept properly sealed and stored, unopened sparkling water can last 9-12 months past its printed expiry date before going flat. The airtight bottle helps retain carbonation by preventing CO2 from escaping into the air. An unopened bottle kept in cool, dark storage may still be lightly bubbly up to a year after expiry.

Storage temperature

Storing sparkling water at cooler temperatures helps extend its shelf life after the expiration date. Storage below 10°C is ideal for maintaining carbonation. The cool conditions help dissolve more CO2 in the liquid. Storage at room temperature accelerates CO2 loss through the bottle walls and cap threads over time.

Bottle material

Plastic PET bottles help prevent gas escape better than glass, keeping sparkling water bubbly for longer. Cans provide the best preservation since they are completely impermeable to CO2. Drink cans can keep sparkling water carbonated for well over a year past its expiry date if the seal remains intact.

Carbonation level

Higher carbonation levels also prolong freshness past expiration. Heavily carbonated waters have more dissolved CO2 to lose before going flat. Many sparkling waters are bottled at 3-4 volumes of CO2 compared to only 1.5-2.5 volumes in soft drinks. This higher carbonation gives a longer shelf life.

Does opened sparkling water expire?

Yes, opened sparkling water expires quickly and only lasts 1-2 days in the fridge before going flat. Once exposed to air, the carbonation rapidly escapes the liquid. An opened bottle or can of sparkling water may lose 70% of its bubbles within the first 24 hours after opening and be mostly flat after 48 hours.

Using a stopper

Putting a tight-fitting stopper on the opened bottle can help retain carbonation for slightly longer. Stoppers minimize air contact to slow the escape of CO2 gas. However, stoppers only extend life by up to 3-4 extra days. The sparkling water still loses potency over time.

Transferring to a sealed container

Pouring opened sparkling water into an airtight thermos or container with no air space can also prolong carbonation for a few more days. Avoid transferring to containers where the liquid sloshes around and agitates remaining bubbles. But overall, opened sparkling water fizzles out quickly no matter how it is stored.

Using a SodaStream

If you have a SodaStream or other carbonation device at home, you can re-carbonate flat sparkling water. Add several spurts of CO2 to revive some bubbles. However, this does not replace lost flavors in flavored sparkling waters. And the texture is not quite as effervescent as a freshly opened bottle.

Does sparkling water need to be refrigerated after opening?

No, refrigeration is not required to keep opened sparkling water safe to drink. However, chilling is recommended to help slow the loss of carbonation. The cool fridge temperature allows more CO2 to remain dissolved in the liquid. Storing opened bottles at room temperature accelerates the escape of bubbles.

Bacterial growth risk

There is no risk of bacterial growth in opened sparkling water. The carbonated water lacks nutrients to support microbial growth, and has antimicrobial carbonic acid. Leaving opened bottles at room temperature does not pose contamination issues.

Fridge space

Once opened, sparkling water has a very short shelf life before going flat. Don’t take up valuable fridge space storing many bottles. Keep only a few chilled opened bottles on hand. Replace them frequently with fresh ones for optimum Enjoy sparkling water soon after opening for best taste.

Temperature preference

Many people prefer to chill sparkling water before drinking for refreshment. The cool temperature enhances carbonation sensation on the palate. Flat sparkling water may be less appealing at warm room temperature. If you want to enjoy opened bottles over a few days, refrigeration helps preserve taste.

How to tell if opened sparkling water has gone bad?

Flat, tasteless carbonated water is the main sign opened sparkling water has expired and is no longer enjoyable to drink. Bubbles disappear within 1-2 days after opening, leaving water with a flat, insipid taste. Flavored waters may also taste dull or slightly off if stored too long after opening.

No bubbles

Lack of visible carbonation is the surest indicator opened sparkling water is past its prime. Tilt the bottle to see if any bubbles rise up. Completely flat, non-effervescent water has gone flat and lost its appeal.

Off or dull flavors

For flavored sparkling waters, faded or odd flavors signal the product is oxidized and no longer tasty. An opened bottle that tastes flat and lacks the bright, crisp flavors of a fresh bottle should be discarded.

Cloudiness or particles

Cloudy deposits or bits floating in opened sparkling water may indicate contamination, though this is extremely rare. Discard any bottles that seem hazy or filled with sediment instead of transparent. But in most cases, flat or stale taste is the main issue.

Can you re-carbonate expired sparkling water?

It is possible to add carbonation back to flat, expired sparkling water using a home soda maker device like SodaStream. The CO2 cartridges infuse bubbles back into the flat liquid. However, this will not restore degraded flavors in flavored waters. The taste may still be off.

SodaStream method

Pour expired sparkling water into the SodaStream bottle. Attach to device and press the carbonation button 2-3 times to inject CO2. This will create small bubbles. Shake bottle before opening to distribute bubbles. The carbonation level won’t be quite as high as original.

Adding baking soda

Adding a pinch of baking soda to flat sparkling water and gently stirring briefly can generate a few bubbles. The baking soda provides additional carbonate ions. However, results are mild and temporary. Bottles go flat again quickly after opening.

Adding lemon or lime juice

Citrus juices contain acids that react with water to form carbon dioxide, creating a few bubbles. However, the juice also changes flavor. Results are very mild with no long-lasting carbonation. This works better on plain versus flavored water.

Does freezing extend shelf life of sparkling water?

Freezing unopened sparkling water can help maintain its freshness past the expiry date. The low freezing temperature causes virtually no loss of carbonation. Frozen storage essentially pauses chemical reactions that degrade bubbles and flavors over time.

Thawing effects

Bubbles remain fully intact immediately after thawing frozen sparkling water. However, condensation forms on the thawed bottles that can lead to some gas loss through the cap over days. Drink thawed sparkling water soon to maximize carbonation.

Avoid freezing opened bottles

Do not freeze opened bottles of sparkling water. The ice expansion can rupture bottles, especially plastic. Opened sparkling water also oxidizes quickly after thawing. Only freeze unopened bottles and consume right after defrosting.

Storing flat sparkling water

Flat, expired sparkling water can be frozen for uses in cooking where carbonation is not needed. Use thawed flat water for making broths, beverages, or any recipe requiring water. Freezing prevents further degradation in taste.

Does sparkling water lose nutrients when it expires?

No, sparkling water does not contain any nutrients like vitamins, minerals, or antioxidants that degrade over time. It is simply carbonated water. Any added flavors also do not provide nutrients. So there are no nutritional losses when sparkling water expires and goes flat.

Original mineral content

Sparkling water gets its minerals like magnesium, calcium, and potassium from the original municipal water source. These minerals remain intact for years, regardless of expiration. Flat, expired sparkling water has the same mineral composition as fresh.

No vitamins

Unlike juices, sparkling waters contain no vitamin C or B vitamins that could degrade over time. There are no vitamins that sparkling water could lose through storage or expiration. The carbonated water provides no nutritional value.

Added flavors

Natural flavors and non-nutritive sweeteners added to flavored sparkling waters also contain no vitamins or minerals. Expired flavored waters do not suffer any nutrient losses. The main impact is potential loss of aroma and taste.


Drinking sparkling water that is past its expiration date is generally not harmful or dangerous. Unopened bottles may last up to a year, retaining slight carbonation when properly stored in a cool place. However, opened bottles go flat within 1-2 days. The main issue with expired sparkling water is loss of bubbles and potentially some degradation in taste, especially in flavored varieties. But there are no safety or nutritional concerns. Expired sparkling water does not spoil or go bad in any way that makes it unsafe to drink.

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