Knowing the importance of water, many people leave a glass of water on her nightstand before going to bed in case you should wake up at night feeling thirsty. And all who have done this or do it regularly will know the strange taste of this water is in the morning.
Regular water unlike food does not contain sugars or proteins that microbes feed on. Therefore, we can not say that it is microbes that realize their strange taste.
Furthermore, the water remaining in a glass is more susceptible to dust particles and bacteria airborne.
On the other hand, when the water is exposed to air, it absorbs carbon dioxide, a small part of which becomes carbonic acid. In other words, this implies that the water is exposed to air is prone to change their chemical structure. To be more specific, carbon acid is converted into carbonate or bicarbonate to publicize one or two protons, which in turn changes the pH of the water. This change also affects the taste.
Although this does not necessarily mean that the water that has been in her nightstand overnight is harmful to drink, it is definitely something worth considering due to the fact that this water has collected a lot of dust and airborne bacteria. So, the next time you feel thirsty to wake up, just jump into your kitchen and get some fresh water instead.
Source: Health Advisory Group