Yesterday my Dad and I went to the county fair. It was hot and one of the most popular booths was one selling bottled water contracts to homes and businesses. It was popular because they has several of those water coolers out with “Free Samples” signs on them. The problem with their concept was that the water coolers didn’t seem to be plugged in and the water was anything but cool. In fact you could have just about brewed tea in it.
Parched from the summer sun, I took a cup and filled it up. I took a drink and grimaced at the taste. Eeeyuck!! It was awful!
My question is: why does water taste so much better cold? I would think it’s chemical changes in the minerals present but bottled water is supposed to be filtered and all that. How many minerals could there be?
If the water was standing in the heat the taste of the plastic container may have been extracted into the water.
Another thing is the solubility of gases in the water. As the temperature increases, gases become less soluble and the water becomes ‘flat’. Dissolved gases improve the flavour of water. That is why you should not boil water for too long when making a tea.
As far as minerals go, as the temperature decreases minerals become less soluble (except calcium). An increase in temperature in this case would not increase the concentration of minerals because the minerals are already in the container - unless you add more.
Also your senses of taste and smell work better on warm things; partly because they are driven by chemical reactions that increase in activity as the temperature rises and partly because they are sensitive to volatile compunds that exist in vapour form when warm.