Did you know that the human tongue can actually taste the flavor of carbon dioxide in the bubbles of fizzy drinks? This might explain why flat soda, champagne, etc. aren’t as enjoyable as drinking it fresh. According to scientists, taste receptors on the tongue which detect the flavor of sour food can also respond to the gases of carbonated or fermented drinks. Neuroscientist Charles Zuker of Columbia University discovered that a class of taste-receptor cells in the tongue respond to carbon dioxide, and specifically identified an enzyme called carbonic anhydrase 4 in the detection of the gas. Continue reading for more.