At least three of our basic taste receptors—sweet, bitter, and umami, or savory—are extremely temperature sensitive. When food or drinks cool the tongue to below fifty-nine degrees, the channels through which these three taste receptors message the brain seem to close up, and the resulting signal is extremely weak. This is why a warm Coca-Cola or a melted ice cream is so sickly sweet: because they’re intended to be consumed cold, they have to contain too much sugar to boost the signal and register in our brains as tasting sweet at all.[*8]
