I moved to Spain about a year ago and at one of my first meals in Madrid, I saw a handsome young couple drinking some kind of unidentifiable light brown cocktail on ice with a wedge of orange and green olives. It was before noon and I was stumped. I had to know what it was. Vermouth, they told me.Before I moved to Spain, I knew of two types of vermouth: white and red. So I had to try it — and it was delicious. Lighter, more subtle, more medicinal than anything I’d had in America.And it’s a lot more than a drink. Vermouth is to Spain what a pint is to Ireland or mate is to Argentina — a national pastime. It’s a lifestyle, as much an activity as it is a beverage. There are establishments called vermuterias here. Historically, people drink vermouth on Sunday mornings after church. In fact, i...