why the water gets strange taste in the morning?

Who never left a glass of water without a lid beside the bed and, while drinking in the morning, he felt a strange taste?
The "phenomenon" is actually common, but it is not so easy to find someone to explain. Some chemical sought by the report failed.

"There is no question that many of us usually receive, or even on which already reflect before," said Professor Susan Richardson of the University of South Carolina, in the United States. She herself had to consult some colleagues working with water supply to respond to the request of a US magazine recently. And look what Richardson does research with drinking water for 26 years.

One of the culprits by changing the flavor, according to the professor, is chlorine, which is very volatile and dissipates quickly in the air. A discrete amount of carbon dioxide may also end up dissipating in the water that is exposed, forming carbonic acid. The result? A slight acidity that makes different tastes.

"It's very difficult to have a pure water sample for a long time," said the professor, adding that other gases such as acetone and aldehydes can also invade the glass. It is worth mentioning that in experiments, the chemical must always rely on pure water so that the results are not changed.
Solutions

Not to quench your thirst and then to grimace, the recommendation is to keep the capped glass. Especially if you decide to leave water in the fridge before going to the room - in this case, other food molecules can dissipate moisture and attack your open cup.

A cover also protects the net of any micro-organisms that are in your room, as well as mosquito larvae. If you happen to leave to take the water only after a few days, not only feel a bad taste but also may even get sick.

Even if you keep the protected glass, there is another factor that could reduce your pleasure by taking the water in the morning, as explained by the teacher: the temperature.

It is the cold water generally has more dissolved gases. Outside that, the more cold drink, the higher the damping of taste buds and as a result, milder taste. For their bedside water to keep fresh the morning, the solution may be to use a thermal cup or bottle.
Bottle

Means that water by itself, does not spoil with time if you're protected?
But then why the bottles you buy at the supermarket have expiration dates and storage rules?

In this case, the culprit is a plastic which has a certain permeability which can result in contamination. The material can also free up some elements when heated.

Finally, if you often reuse their plastic bottle at home or at work, remember to sanitize them often. Simple constant contact of the bottle and the cap with your hands can be enough to contaminate it.

A study published in the Canadian Journal of Public Health, 76 bottles of water samples used in a school, a number of detected above the acceptable fecal coliforms in 64% of them. These bacteria can cause diarrhea and food poisoning, for example