Does Bottled Water Go Bad? HowStuffWorks Bottled water often carries an expiration or best by date, but pure water itself does not expire or spoil, as it lacks nutrients for bacteria growth. The date primarily concerns the plastic bottle: Your eyes are your first line of defense. Good BAC Water: Crystal clear, odorless (faint alcohol scent), and painless. Bad BAC Water: Cloudy, particulate matter, strong chemical smell, or severe burning. Bac Water Expiration