This is why your bed-side glass of water went off during the night
You are getting ready to doze off into the night’s sleep and just to make sure you don’t need to get up from the bed if you get thirsty, you put a chilled glass of water next to your bed. You didn’t wake up during the night, but in the morning you had a sip from that glass and realise that the water isn’t tasting the same way it did the night before! What is that?
This is a question that has been thought off many times, but no one actually asked it to the right set of people. The answer is quite simple! The increase in temperature is causing the water to go off. When the water is chilled, the pongs inside it are sort of hidden. As temperature rises, its real taste and smells (aroma) are revealed and that’s the reason your bed-side glass of water tastes different.
When asked by Wired, Susan Richardson, a chemist at the University of South Carolina, said that during her 26 years of research on drinking water, she had never thought about it. “It’s the simple things that nobody thinks about,” she says.
Richardson does add that temperature doesn’t really answer the whole mystery. Dissolved gases are also to blame. As water sits out small amounts of carbon dioxide (CO2) dissolve into the water forming carbonic acid, which may lower the pH just slightly. This could also change the taste of water.
Then there is chlorine which also plays a role. Water treatment plants add chlorine to get rid of potentially deadly pathogens. Chlorine is volatile and quickly dissipates into the air when left open. However, we are used to drinking conditioned water directly from tap and that’s why when the glass of water is left on the bed-side, that freshness that chlorine provides dissipates leaving you with a rather musty or heavy or even oily taste.