Water doesn’t have a true expiration date — but it can still go bad. For emergency supplies, it’s important to know how long bottled water, tap water, and spring water actually stay safe to drink.
How Long Does Bottled Mineral Water Last?
The best-before date printed on water bottles is not a quality indicator for the water itself — it refers to the packaging. PET bottles gradually release microplastics and plasticizers into the water over time.
- Unopened PET bottle: Officially 6–24 months according to the label. The water itself remains drinkable longer, but quality declines.
- Unopened glass bottle: Virtually unlimited shelf life.
- Opened bottle: Use within 3–5 days.
Recommendation: Rotate your water supply every 12 months — use the older water, buy new.
How Long Does Self-Filled Tap Water Last?
If you fill your own containers with tap water:
- In clean, airtight containers: 6–12 months
- In regular bottles: 3–6 months
Important: Rinse containers beforehand with drinking water and a drop of household bleach. Store in a cool, dark place. Replace every 6 months.
Signs That Water Has Gone Bad
- Cloudy, greenish, or brownish tint
- Unusual smell (musty, chemical)
- Visible particles or sediment
- Slimy film on the inside of the bottle
When in doubt: treat it (filter, boil) rather than drink it directly.
Proper Storage for Your Emergency Supply
| Container | Shelf Life | Tip |
|---|---|---|
| PET bottles (original) | 12–24 months | Rotate annually |
| Food-grade jerricans | 6–12 months | Fill clean, store in the dark |
| Glass bottles | Unlimited | Watch out for breakage |
| Collapsible containers | 6 months | For temporary storage only |
Golden rules:
- Store cool (below 68°F / 20°C) and dark
- Not near cleaning products or chemicals
- Not directly on the floor (temperature fluctuations)
- Label containers: write the fill date on them
What If Your Supply Runs Out?
No problem — if you’re prepared. With a good water filter you can turn water from streams, rain, or standing water into safe drinking water.