Does Bottled Water Go Bad?

The “Big Four” brands of bottled water — Dasani, Aquafina, Glacéau Smart Water and Nestlé Pure Life — each account for $1 billion in annual sales in the U.S. alone. Although people drink most of it pretty quickly, some might stock up on it for emergencies, or if they get a great deal on it. So, is storing bottled water for a few months (or years) a bad idea? You may have seen a “sell-by” or “best used by” date on your bottle of water, but what does that mean? Can water expire? The water isn’t actually the issue when it comes to expiration, because H2O doesn’t have any sugar, proteins, or additives that typically cause food to spoil. The packaging is the real culprit. The vast majority of bottled water is packaged in plastic, and they’re ever-so-slightly porous, which may allow ambient air gases such as vapors from household solvents, petroleum-based fuels, and other chemicals to affect the taste and odor of the water. Storage is the key to preserving bottled water. Studies have shown that antimony — a chemical in many plastic bottles — can get into water if it’s stored at high temperatures over a number of weeks. Bottled water should be stored at least at room temperature — ideally cooler if possible — and kept away from direct sunlight and household chemicals. Both excessive heat and sunlight can cause mold or algae to develop in the water. So, think twice about leaving that case of water in your car over the summer.