That dry, mouth-gripping sensation in the first sip of a young Barolo has a name: tannin. It's the invisible backbone of wine, the substance that binds salivary proteins and turns your tongue to sandpaper. But it's also what allows great reds to age for decades. Where does it come from? How is it extracted? And why does Maria Teresa Mascarello continue to macerate her grapes for up to 50 days, just as her father did? A journey through the chemistry and sensory world of wine.
