Humans are particularly sensitive to bitterness. Thanks to a small but novel family of 30 genes, we can perceive thousands of bitter compounds. Our ability to discern bitter tastes evolved as a way to keep our early ancestors from eating poisonous plants.
Bitterness is a taste sensation that we experience when monomeric flavonoid phenols, the compounds that are responsible for bitterness in wine, reach the bitter taste receptor cells on our taste buds. As the receptors send electrochemical signals to the gustatory cortex, we experience bitterness. To what degree determines whether we consider a wine to be merely complex, flawed or faulted. Read the entire article here –Bitterness June July 2016