Scientists in Cuba have been exploring the reason that tepid beverages do not taste as good as hot ones.
The problem with lukewarm coffee dates back to the days of cavemen, according to Karel Talavera of the Laboratory of Ion Channel Research. Their ‘taste receptors’ evolved according to the food they ate, and our own modern-day taste buds still work according to the same format.
The researcher has studied the way that taste receptors respond to molecules at different temperatures. Human taste receptors are most sensitive to food molecules at 20c-35c (68-95F), or just above room temperature, and do not always register molecules outside than this range.
Therefore, hot coffee at around 170 F may seem less bitter than room-temperature coffee simply because at that temperature, human taste receptors are not as sensitive to the bitter molecules in the coffee.
The reason that human taste buds do not work at extremes, says Talavera, is a historical one. Early man existed on foraged berries and freshly-hunted meat, which had ambient temperatures of 20c-37c, and that is why human taste buds are most sensitive in that area. Because hot or iced beverages fall outside this range consumers do not recognise a drink’s true bitterness.
Other researchers have argued that the bitterness of tepid coffee has more to do with smell than taste. A ‘taste perception scientist’ at Yale University says that hot coffee releases more aromatic compounds than room-temperature coffee, so it has a greater chance of impacting human sensors.