My roast chicken tastes great straight out of the oven, but the refrigerated leftovers are always bland. Why is that?
The explanation is twofold: First, scientists have discovered that our ability to taste is heightened by microscopic proteins in our taste buds that are extremely temperature-sensitive. These proteins, known as TRPM5 channels, perform far better at warm temperatures than at cooler ones. In fact, studies have shown that when food cooled to 59 degrees and below is consumed, the channels barely open, minimizing flavor perception. However, when food is heated to 98.5 degrees, the channels open up and TRPM5 sensitivity increases more than 100 times, making food taste markedly more flavorful.
Second, much of our perception of flavor comes from aroma, which we inhale as microscopic molecules diffuse from food. The hotter the food, the more energetic these molecules are, and the more likely they are to travel from the table to our nose.
The lessons? Dishes meant to be served hot should be reheated, and dishes served chilled (like gazpacho or potato salad) must be aggressively seasoned to make up for the flavor-dulling effects of cold temperatures.