Experts note that the subtle chemical changes that happen overnight, can really change the composition of the water, making it slightly acidic.
If you have ever left a glass of water on the bedside table at night, you may have noticed that in the morning she has a bit of a strange taste.
And this is completely irrelevant to the excessive fault-finding – thin chemical changes that happen overnight, can really change the composition of water, which makes it a little sour, experts say. To not worry – these changes are not dangerous.
Water does not contain protein or sugars, so the microbes can cause its decomposition, as it usually happens with food. But the chemical composition of water changes as it remains open to the air and absorbs some amount of carbon dioxide, making it slightly more acidic.
These changes are the reason why bottled water has a limited shelf life. A tiny fraction of the absorbed water, carbon dioxide turns into carbonic acid. This reduces the pH of water making it slightly acidic and slightly alter the taste.
Experts also note that global levels of acidity in the world’s oceans have risen since the industrial revolution, in connection with the additional appearance of carbon in the air. A small change of acidity in a glass of water won’t hurt you, however, large reservoirs, which are exposed to the air for a long period of time, may become contaminated with various bacteria.
This can lead to growth of algae and mosquito larvae. For this reason, many sailors took the beer and rum on a long trip, as the alcohol neutralize the microorganisms that can grow in fresh water.
As for bottled water, it can be safe indefinitely, as long as stored properly. The plastic is slightly permeable – this means that it should not be near hazardous chemicals.
Some plastics also release a substance called bisphenol a into the water when heated, so water bottles should not be stored in direct sunlight.
