If you’re talking about store-bought bottled water: check the expiration date. Yes, water itself doesn’t go bad, but the plastic bottle does over time. Most manufacturers stamp a two-year date from bottling, but that’s more about bottle quality than water quality.
For tap water you filled yourself? You’ve got about six months in a cool, dark place. After that, it’s not a poison—it just starts tasting like your gym bag.
So, no, you won’t turn into a zombie from old bottle water. But your taste buds might file a complaint.
