How Long Does Bottled Water Last?
The short answer: the water itself doesn't expire. Water is water. It doesn't go bad the way milk or produce does. What changes over time is the plastic bottle holding it, and that's a meaningful distinction most people miss.
Here's what you actually need to know about bottled water shelf life, what those dates on the label mean, and how storage affects what you're drinking.
Does Bottled Water Actually Expire?
No. Pure water has no expiration date. The FDA doesn't require one. The dates you see on bottled water are manufacturer-stamped packaging dates, not safety cutoffs.
New Jersey was the first state to require expiration dates on bottled water, back in 1987. The FDA followed with a federal rule in 1996. But in 2002, the FDA reversed course and removed the requirement, concluding that water doesn't expire. Most brands still print dates anyway, partly out of habit and partly because retailers use them for inventory rotation.
So when you see "Best By 12/2027" on a water bottle, that date has nothing to do with the water going bad. It's a packaging date.
What the Date on the Bottle Actually Means
The date on a water bottle is about the container, not the contents. Plastic bottles, specifically PET (polyethylene terephthalate), the material used in most single-use water bottles, can leach small amounts of chemicals into the water over time. The main concern is antimony, a metal used in PET production, and acetaldehyde, which affects taste.
A 2014 study in Water Research found that antimony levels in bottled water increased with storage time and temperature, though levels remained well below EPA safety thresholds in most cases. The bigger practical issue is taste: water stored in plastic for a long time, especially in warm conditions, starts to taste slightly off. Not dangerous. Just not great.
The date on the bottle is essentially the manufacturer's estimate of when the water will still taste the way it's supposed to taste. After that, the water is still safe to drink. It just might not taste as clean.
Sealed Bottled Water Shelf Life by Container Type
Container material makes a significant difference. Here's how long sealed bottled water stays at its best, by type:
| Container Type | Shelf Life (Sealed) | Notes |
|---|---|---|
| Single-use plastic (PET) | 1–2 years | Leaching increases with heat and UV exposure |
| 5-gallon plastic jugs (HDPE) | 1–2 years | HDPE is more stable than PET but still degrades |
| Glass bottles | Indefinite | No leaching; taste stays consistent indefinitely |
| Aluminum bottles | Indefinite | No leaching; light-blocking protects water quality |
Glass and aluminum don't leach. There's no chemical interaction between the container and the water, so the water stays exactly as it was when it was bottled. That's why aluminum bottled water has an indefinite shelf life, and why it's a better long-term storage option than plastic.
Opened Bottled Water Shelf Life
Once you open a bottle, the clock starts. Exposure to air introduces bacteria, and if you're drinking directly from the bottle, you're also introducing bacteria from your mouth.
- Refrigerated: 2–3 days. Keep it capped between uses.
- Room temperature: 1 day. After that, bacterial growth becomes a real concern.
- Left in a hot car: Drink it that day or toss it. Heat accelerates both bacterial growth and plastic leaching.
The 2–3 day refrigerated guideline applies to water you're drinking from directly. If you pour from the bottle into a glass each time and keep it capped, it'll stay fresh longer. But most people don't do that, so the 2–3 day rule is the practical one.
Signs Bottled Water Has Gone Bad
Water doesn't spoil in the traditional sense, but it can become unpleasant or, in rare cases, unsafe. Here's what to watch for:
- Plastic taste or smell: The most common issue with old plastic bottles. The water is probably still safe, but the taste is off from chemical leaching.
- Algae growth: Green or brown discoloration in a clear bottle means algae. This happens when water is exposed to sunlight for extended periods. Don't drink it.
- Cloudiness or sediment: Could be mineral deposits (harmless) or bacterial contamination (not harmless). If you're not sure, don't drink it.
- Off smell: Fresh water has no smell. If it smells like anything, something is wrong.
For sealed, properly stored water in a non-plastic container, none of these issues apply. The problems above are almost exclusively associated with plastic bottles stored in poor conditions or opened water that's been sitting too long.
How to Store Bottled Water to Extend Shelf Life
Storage conditions matter more than the date on the label. The same bottle of water stored in a cool, dark pantry will taste better two years from now than a bottle stored in a hot garage for six months.
The rules are simple:
- Keep it cool. Ideal storage temperature is 50–70°F. Avoid garages, car trunks, and anywhere that gets hot in summer.
- Keep it dark. UV light degrades plastic and can promote algae growth in clear bottles. A pantry or cabinet is better than a windowsill.
- Keep it away from chemicals. Plastic is slightly permeable. Storing water bottles near gasoline, cleaning products, or paint can cause those chemicals to migrate into the water over time. This is a real concern for emergency water storage in garages.
- Don't freeze and thaw repeatedly. One freeze is fine. Repeated freeze-thaw cycles stress the plastic and can cause micro-cracks that affect seal integrity.
For long-term emergency storage, glass or aluminum containers are the better choice. They're not affected by temperature swings, don't leach, and don't absorb odors from nearby chemicals.
Frequently Asked Questions
Can you drink bottled water past the expiration date?
Yes. The date on bottled water is a packaging date, not a safety cutoff. Water stored in good conditions past its printed date is safe to drink. The taste may be slightly off if it's been stored in plastic for a long time, but it won't make you sick.
How long does bottled water last in a hot car?
Drink it the same day or throw it out. Heat accelerates plastic leaching and bacterial growth in opened bottles. A sealed bottle left in a hot car for one afternoon is probably fine, but repeated heat exposure degrades the plastic and affects taste. Don't use your car as long-term water storage.
Does bottled water go bad if frozen?
No. Freezing water doesn't affect its safety or quality. The concern with freezing plastic bottles is that the plastic can crack if the water expands too much, which could compromise the seal. But the water itself is fine. Thaw it and drink it.
How long does 5-gallon water jug last?
Sealed, 1–2 years. Once opened and on a dispenser, use it within 30 days. The large opening on a 5-gallon jug exposes more water surface area to air, which speeds up contamination. Keep the dispenser clean and replace the jug regularly.
Is it safe to reuse plastic water bottles?
Single-use PET bottles aren't designed for repeated use. The plastic degrades with washing, and the narrow mouth makes them hard to clean properly. If you want a reusable bottle, get one designed for it, stainless steel or glass. Reusing single-use bottles isn't dangerous in the short term, but it's not ideal.
Does bottled water expire if unopened?
Not in any meaningful safety sense. Unopened water in a glass or aluminum container stays fresh indefinitely. Unopened water in plastic stays safe but may develop a plastic taste after 1–2 years, especially if stored in warm conditions.
The Bottom Line
Water doesn't expire. The bottle does. If you're storing water for emergencies or buying in bulk, the container choice matters more than the date on the label. Glass and aluminum don't leach, don't absorb odors, and don't degrade over time. Plastic does all three, slowly.
For everyday use, a sealed plastic bottle stored in a cool, dark place is fine for 1–2 years. Once opened, drink it within a day or two. And if it smells like anything other than nothing, trust your nose.
If you're looking for water with a genuinely indefinite shelf life, aluminum bottled water is the answer. No plastic, no leaching, no expiration date. Or if you're buying for a business or event, private label water in aluminum is worth a look.
For more on what's actually in your water, see bottled water vs. tap water and the best water to drink.