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Does Water Expire? How Long Does Water Stay Fresh?

You’ve likely seen branded bottled water in stores with an expiration date on the label. This seems odd – how can water itself expire? The details on water freshness, shelf life and expiration are more complex than you might expect.

This article will examine the factors that influence how long water stays pure and palatable. You’ll learn how elements like container material, temperature and exposure impact shelf life. We’ll also cover maintaining freshness with purification systems like Artic Refresh.

Can Water Go Bad?

Let’s first establish some fundamentals about water:

  • Water molecules themselves do not expire or go bad. H20 is an intrinsically stable molecule.
  • However, water can become contaminated by outside influences. Microbes, chemicals, particulate and environmental exposure all threaten purity and freshness.
  • Stale water also takes on unpleasant odors, colors and tastes indicating it should be discarded and replaced.

So while pure H20 remains indefinitely stable, factors external to the water itself very much determine freshness and when you should replace suspect water.

Do Bottled Water Expiration Dates Matter?

Let’s start by examining why bottled water is assigned an expiration date, typically 2 years after bottling:

Plastic Leaching

Even high-grade food plastics still allow tiny amounts of compounds to diffuse into the water slowly over months, altering taste.

Stale Tastes

Similarly, water sitting for prolong periods picks up plasticy, stale tastes from the bottle material and caps.

Nutrient Degradation

Bottled water containing added electrolytes or vitamins see these supplemental ingredients degrade over time.

Safety Margin

Allowing for some shelf life provides a safety margin should water sit unsold well past bottling.

So the marks offer some buffer assuming less than ideal storage. But what do the dates actually mean?

Are Expired Bottled Waters Unsafe?

Here is the consensus among regulators and chemists:

  • Bottled water 2+ years past its date remains generally safe if unopened. Chemical leaching is quite minimal and stable sealed containers prevent microbial issues.
  • However, older water may take on plasticy odors or tastes indicating declining freshness. Freezing can accelerate absorption.
  • Exposed to heat and sunlight, chemical leaching occurs more rapidly as plastic degrades. Toxicity remains low though.
  • Bottlers assume some stock will remain unsold for a year or more. Dates provide a buffer against claims of selling “bad” water.

While not harmful per se, best practice is to consume bottled water within 6-12 months for optimal taste and nutrient retention if contained.

Does Tap Water Go Bad in Pipes?

What about tap water sitting unused in home and building pipes? Things that reduce freshness include:

Microbial Growth

Pipes develop interior biofilms that shed bacteria into first-flowing water after prolonged stagnation.

Sediment Release

Iron, manganese and scale deposits built up in piping slough into stagnant water.

Chemical Leaching

Metals like lead or copper from aging pipes leach into untapped water the longer it sits.

Plastic Absorption

PVC, PEX and other plastic tubes allow chemical diffusion into water over time.

This is why experts recommend fully flushing tap lines first thing in the morning or when returning from long trips before drinking the water. Stagnation degrades municipal water quality.

Can Bottled Water Go Bad After Opening?

Once opened, bottled water has a shorter shelf life. Exposure to light, oxygen and microbes rapidly reduce freshness:

Microbial Colonization

Over time, bacteria from your mouth and dust can proliferate in the bottle.

Temperature Fluctuation

Heat expansion and contraction accelerates chemical leaching from plastic.

UV Light Damage

Sunlight exposure generates free radicals converting stable compounds into reactive chemical species.


Dissolved oxygen reacts with organic minerals like iron to form precipitates and metallic tastes.

General guidance is to drink opened bottled water within a week and discard thereafter for best flavor and purity. Keep unused bottles sealed and refrigerated.

Can Tap Water Go Bad in Reusable Bottles?

Like stored bottled water, tap water also declines when kept reused in bottles:

Bacterial Growth

Refilling bottles allows microbial contamination and biofilm buildup over time.

Absorption From Container

Compounds from plastic bottles and lid materials leach into contents, especially if scratched.

Dirty Containers

Reusing unwashed bottles accumulates residues altering taste/smell.

Sun Exposure

Heat and UV light catalyze chemical breakdown of water and plastic faster.

This is why it’s recommended to wash reusable bottles thoroughly after each use and let them fully air dry. Avoid storing water long term in the same container. A weekly bottle swap is ideal.

Does Water Go Bad After Freezing?

You might think freezing water stops the clock on freshness, but frozen water experiences changes too:

Absorbent Residues

Freezing concentrates any dissolved solids and particles making the thawed water taste different.

Plastic Leaching

Freezer temperature exaggerates diffusion from plastic bottles into the water.


Dissolved oxygen previously depleted by microorganisms rapidly re-enters thawed water.

For best quality, use frozen water within 3-6 months. Avoid refreezing frozen water.

Does Distilled Water Go Bad?

With potential contaminants removed, distilled water enjoys greater longevity before going “bad”:

  • Sealed distilled water can remain fresh 3+ years if protected from light and heat.
  • Distillation removes metals, minerals and microbes increasing shelf life.
  • Opened distilled water in clean containers can last 6-9 months before tasting flat.
  • Without supplemental electrolytes, distilled water lacks flavor when newly opened but is not harmful.

Distillation provides a blank slate – quality thereafter depends on storage and handling. Refrigerate opened distilled water.

Does Purified Water Go Bad?

Like distillation, purified water also lasts longer before expiring:

  • Multi-stage reverse osmosis filtration removes nearly all dissolved solids for long-lasting purity.
  • UV treatment kills microbes while filtration removes pathogens to inhibit contamination.
  • Antimicrobial dispensers prevent microbes entering outputs of purification systems.
  • Routine maintenance like tank cleaning and filter changes maintain freshness.
  • Open purified water optimally lasts 1-2 months before tasting stale as oxygen dissipates.

Purified water from advanced systems like Artic Refresh remains fresh far longer than tap or bottled thanks to rigorous contaminant removal.

How Long Does Deionized Water Last?

Deionized water has the longest shelf life before degradation thanks to complete removal of dissolved ions and molecules:

  • Sealed containers of deionized water stay pure 12+ months before absorbing CO2 and leaching packaging organics.
  • Open deionized water readily absorbs from the atmosphere but remains safe indefinitely if contamination prevented.
  • Additional membrane filtration after deionization removes remaining organics and microbes for maximum longevity.
  • Deoxygenation via nitrogen blanketing extends shelf life by preventing oxidative reactions.

Of common waters, deionized enjoys the longest stable shelf life thanks to its exceptional purity. But it lacks taste and electrolytes.

Maintaining Water Freshness With Artic Refresh

While water sitting around inevitably becomes unpalatable over time, sources like Artic Refresh deliver freshly purified water on demand:

  • Our reverse osmosis process removes contaminants down to 0.0001 microns in size for clinical purity.
  • Chilled storage tanks keep water cold, limiting microbial growth and chemical interaction.
  • Antimicrobial components prevent buildup of bacteria near dispensing nozzles.
  • Routine professional cleaning and tank flushing sustains sanitary conditions.
  • Constant flow means water sits minimal time versus warehousing.

Drink confidently knowing Artic Refresh machines reliably provide clean, refreshing drinking water that hasn’t stagnated or lingered collecting contaminants.

How Long Does Water Stay Good in Storage?

To recap, here are general freshness guidelines based on container and conditions:

Sealed Bottled Water – 2-3 years before tasting stale

Opened Bottled Water – 3-5 days optimally, 1 week maximum

Tap Water in Pipes – Flush pipes after 1-2 weeks stagnation

Tap Water in Bottles – 3-5 days is best, refrigerate and wash bottle each use

Distilled Water – 1-2 years sealed, 6 months opened

Purified Water – 6 months sealed, 1 month opened

Deionized Water – Over 1 year sealed, 3 months opened

While water itself remains stable eternally, outside factors dictate freshness. Tap water lasts longest before deterioration.

Maintaining Your Water’s Freshness

Here are tips to keep stored water optimally fresh:

  • Use glass containers instead of plastic to avoid leaching compounds.
  • Replace bottles and jugs periodically rather than reusing indefinitely.
  • Refrigerate containers to inhibit microbial growth and chemical reactions.
  • Avoid direct sunlight which degrades plastic and heats water speeding reactions.
  • Never freeze in plastic which concentrates freezer temperatures compound diffusion.
  • Freeze in glass if freezing, limiting duration to 3 months for best results.
  • Flush tap lines thoroughly if water sits more than a few days.
  • Drink tap water immediately versus storing to minimize contact time with pipes.
  • For stored emergency water, rotate containers every 6-12 months.

Proper storage optimizes shelf life, while filtration systems like Artic Refresh provide pure water on demand.

FAQ About Water Freshness

Can you drink bottled water years after expiration date?

While not recommended for peak freshness, unopened bottled water over 2 years past its date generally remains safe to drink as compounds that leach are not highly toxic.

How long does unopened bottled water last at room temperature?

2-3 years is typical before tasting stale. Avoid temperature extremes. Refrigerating extends life slightly but leads to more condensation leaching compounds faster upon warming.

Is it safe to drink expired bottled water if left in a hot car?

Maximum storage temperature for bottled water is 110°F before accelerated leaching occurs. Exposure over days in a hot vehicle likely causes faster degradation and decline in taste. Not acutely toxic but best avoided.

How long does bottled water last after opening?

1 week is ideal for opened bottled water. Discard any bottles where the contents smell or taste abnormal. Keep refrigerated and use clean cups to minimize contamination.

How can you tell if bottled water went bad?

Off odors, cloudiness, foaminess, and abnormal tastes indicate contamination or excessive chemical leaching making water non-potable and requiring throwing it out.

Does purified water go bad?

Highly purified water lasts much longer – a year sealed and 1-2 months opened. Additional filtration, antimicrobial protections, and avoiding light, heat, oxygen extend shelf life. Artic Refresh machines provide freshly purified water.

Can you drink from tap water sitting unused for a week?

It’s recommended to fully flush tap lines for 1-2 minutes first after long periods of stagnation to clear sediment, microbial films and any metals leaching from old pipes.

How long does unopened distilled water last?

Around 2-3 years thanks to removal of contaminants through distillation that would diminish freshness. Opened distilled water lasts 6-9 months before absorbing surroundings. Refrigerate once opened.

Does freezing extend water’s shelf life?

Freezing stops microbial growth but concentrating solutes, oxidizing dissolved gases, and plastic freezer leaching reduce quality. Use frozen tap water within 3 months. Avoid refreezing thawed water.

While water itself doesn’t expire, environmental factors affect purity and freshness noticeably within months to years depending on conditions. Utilize fresh sources like Artic Refresh for drinking.