The FDA and bottled water companies recommend storing unopened water for up to two years. That’s the “best by” date, but it’s not a magical deadline where the water turns into a frog. Manufacturers put that date there because the plastic might start tasting like plastic, not because the water will kill you.
In reality, if you store the bottle in a cool, dark pantry, that water is probably safe for decades. There are stories of hikers drinking 20-year-old emergency water and living to tell the tale—though they admit it tasted like a sweaty gym bag. The key is temperature and light exposure, not a calendar.
