Zachary Golper gets a strange look in his eyes when he talks about his miche.

Mr. Golper, who oversees the ovens at Bien Cuit, a bakery in Brooklyn, is part of a starter culture of obsessive, boundary-pushing bread makers in New York City and around the country. Connoisseurs consider his miche, a French-style country loaf, something of a crown jewel. But it certainly doesn’t shine like one; bulbous and heat-bludgeoned, it looks more like something that might have been used as a shield in a Stone Age skirmish.

Which makes sense. After all, Mr. Golper, like many comrades in the revolutionary salt-flour-water brigade, is engaged in an ancient and ceaseless battle: against the whims of working with fermenting dough whose personality can shift on a daily or even hourly basis; against the high costs of making bread in what he considers the purest manner; against decades of commercialization that have trained the American eye and palate to expect bread that is soft, gummy, pale and tasteless.

“Most people are trying to make bread as quickly as possible,” he said. “I don’t think there’s any reason to make bread fast. I don’t think it’s healthy.”

Instead, Mr. Golper, 36, wages a loving blitz upon the miche dough, fermenting it for up to an epic 68 hours and hardening the crust with a bake that goes on for almost double the time (at a slightly lower temperature) than you would find in the average shop. The dough itself contains six different types of flour.