Santa Cruz Mountains Terroir from Expert Dr. Mark Greenspan ~ Part 2

An old wives’ tale is that you want warm days and cold nights. That came from, I believe, people who were growing wine in warm regions. They have to have a cool night if they have a warm day. But if they have a moderate day, they don’t need that cold night, because the heat that ripens the grapes also metabolizes acids, so they lose acidity.