While we may never even consider eating food that has been left out all night, sometimes keeping that glass of water next to the bed is an easy and convenient way to quench your middle-of-the-night thirst, or early morning need for water. We figure water can’t go bad, so letting it sit out all night is fine for our health. However, it always tastes just a bit different when it is not fresh. This is a warning sign that it may not be as safe as you think. Water should be essentially tasteless in its most pure form. So if it tastes slightly off, it means that foreign molecules have entered the liquid, or the composition of the liquid has changed.
Worst Thing You Do to Your Body in The Morning
Because water does not have the proteins or sugars that food has to target microbes, it doesn’t mean that other bacteria does not accumulate in a glass of water over time. When water is left out in open air, it absorbs CO2, which can be converted into carbonic acid. This, in turn, changes the chemical composition of the water. This changes the taste of the water by lowering the pH level throughout the night. Some subtle, mild chemical changes happen to the water over time, which can make the water slightly more acidic by changing its composition.