There's a comfortable—and mistaken—idea that we make bread. In natural fermentation, this is not true. From a scientific point of view, what we call "making bread" is the management of a complex biological system. Wild yeasts and lactic acid bacteria—mostly from the genera Saccharomyces and Lactobacillus —metabolize the sugars in the flour, producing carbon dioxide, organic acids, and aromatic compounds. These microorganisms structure the dough, develop the flavor, and initia