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: BACTERIOSTATIC WATER 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. Does Water Expire? What You Should Really Know