Mini cupcakes. Kimchee tacos. The cronut. These foods seem to become popular almost overnight, inspiring hungry customers to stand in line for an hour or more just to get a taste. But what makes a particular food fashionable? And what's the deal with San Francisco's $4 artisanal toast craze? We talk with journalist David Sax, who explored these questions for his new book, "The Tastemakers."
We swung by two San Francisco establishments who frequently have lines out the door for their cragels and specialty toast: