Odds are, you’ve eaten pain à l’ancienne before without even knowing it. It’s hard to overestimate the stir this recipe caused when it was unveiled by Peter Reinhart five or six years ago. Up until then, commercial bakeries and restaurants had to rely either on long dough fermentation or artificial methods to get comparable flavor, texture and color in their breads. Pain à l’ancienne was a boon to many of them, since it provided a great rustic bread product in no time, via a virtually idiot-proof process. If you’ve ever eaten a sandwich at a Panera Bread, Corner Bakery or Whole Foods, chances are it was some form of Reinhart’s latest (maybe greatest) gift to comercial bakery.