Bottled water usually has an expiration date stamped on the container, but does it actually go bad? How long is bottled water good? The simple answer is that water is a pure compound that never goes “bad.” It is labelled with an expiration date to comply with state laws and for manufacturer convenience, not because the quality of the water changes over time. While the flavor of bottled water may change over time, it doesn’t become unsafe to drink.
Expiration Dates and State Laws
Why put an expiration date on a product if it doesn’t go bad? You can blame the state of New Jersey, if you like. New Jersey requires all food and beverage packaging (including water) to carry an expiration date. It doesn’t matter whether you actually live in New Jersey or buy water there. It’s easier for manufacturers to standardize packaging. Some bottlers use the containers for other beverages, which might actually expire, so stamping all of them with an expiration date saves money. Also, having a date makes it easier for seller to rotate stock.
Sometimes bottled water has a bottling date or “best by” date. Once again, the dates help manufacturers and sellers track stock. This information helps with bottling errors or product recalls. Also, water flavor may change over time as chemicals are absorbed from packaging. While the flavor may not be bad and the water will remain safe to drink, it won’t taste quite as fresh.
Plastic Leaching and Bottled Water
Toxic and unpleasant tasting chemicals leach from plastic into bottled water. However, most of these chemicals occur in freshly bottled water and don’t appreciably increase over time. If the water has a “plastic” flavor, it’s not an indicator the product is bad. At the same time, water lacking an unpleasant taste isn’t necessarily free of contaminants. It’s better for your health and the environment to minimize bottled water use and choose containers made of glass or other materials.
Extending Bottled Water Shelf Life
So, sealed bottled water remains good pretty much forever. You can minimize additional leaching from the bottle by storing bottled water in a cool, dark location. Once you break the seal, air gets into the container, so algae and bacteria may start to grow. You should consume bottled water within two weeks after opening it. The shelf life of opened bottled water may be extended by refrigerating it.
References
- Food Standards Agency. “Best Before.” U.K.
- Labuza, T. P., Szybist, L. (2004). Open Dating of Foods. Food and Nutrition Press. Wiley-Blackwell. ISBN 0-917678-53-2.
- NPR (February 17, 2017).”New Guidelines Seek to Provide Clarity on Food Expiration Dates.” All Things Considered. U.S.