Water itself is a pretty tough character. Unlike milk that sours or juice that ferments, pure water has no sugars or proteins for bacteria to feast on. So technically, that glass bottle of water you forgot in your car last month is still safe to drink—as long as you didn’t share it with your gym sock.
But here’s the twist: it’s not the water we’re worried about. It’s the container and the environment around it.
Glass versus plastic: the slow-motion race
Glass bottles are the superheroes of the water world. They don’t leach chemicals like some plastics can, and they don’t hold onto old flavors. But even glass isn’t magic. If you leave a glass bottle of water in direct sunlight, especially by a sunny window, tiny algae can start partying in there. It won’t hurt you, but it’ll taste like you’re sipping from a pond.
Think of it this way: your glass bottle is like a cozy apartment. As long as it’s clean and out of the sun, the water stays happy for a very long time.
