©1995, 1999, 2003 Jeff Renner   jsrenner@umich.edu
Sour dough bread has its origins in the times before reliable commercial yeast was available for leavening. A baker had several options available to leaven bread. The local brewer was a source of yeast that, while rather slow and often bitter, was usually reliable. People away from a brewery could make a starter by capturing wild yeast from the environment, a chancy proposition at best. Because of the ubiquitous presence of Lactobacillus spp., this starter would inevitably become sour. In a true starter, wild yeast and bacteria establish a relatively stable equilibrium. When a particularly good starter was found, it would be prized, and the baker would save a portion of the previous dough or sponge in a covered container to use for the next batch. This starter is a very vigorous one that a friend brought me several years ago from a famous Parisian bakery. It is subtly sour, and as a matter of fact, the French object to calling their naturally fermented bread “sour dough.” They prefer the term “pain au levain.” While it isn’t very sour, it is far more flavorful bread than bread fermented with commercial yeast. You can make more sour bread by letting each stage ferment longer than the minimum. (more…)