Hot and Sweet
Why does food taste different when it's hot?
There's no doubt that food tastes different when it's hot. Part of the reason is that heat brings out more of the aroma, and our sense of taste relies a lot on how things smell.
But there's more to it, according to the February 2000 issue of the journal Nature. Heat can stimulate taste buds, so that they send a signal back to the brain. For example, if you put something warm on the front edge of your tongue, you'll get a sensation of sweetness. That's because the nerves that are being stimulated only know how to send one message to the brain: the sensation of sweetness.
The brain can't tell if the nerves were stimulated by a chemical, such as sugar, or something else, such as heat. Cold temperatures usually cause a sour or salty taste.
Maybe that's why a warm soda tastes too sweet, and a cold soda tastes just right.