A wave of high-concept cafés is redefining how Californians get their caffeine fix. In Costa Mesa, reservations-only Theorem (pictured; 3313 Hyland Ave.) serves a multicourse tasting with a touch of molecular gastronomy (the ice cream in your affogato is made using liquid nitrogen). On the purist end, Handsome Coffee Roasters (582 Mateo St.) in downtown Los Angeles has a spare, three-item menu: espresso, espresso with milk, and drip coffee. San Francisco's Linea (3417 18th St.), a standing-room-only bar in the Mission, is even more doctrinaire: it only sells house-roasted espresso, served as cappuccinos or naked in a demitasse.