What are the qualities of sourdough?

Sourdough bread is nutritionally more interesting than bread made with chemical yeast. In fact, sourdough promotes better mineral assimilation and greater breakdown of gluten, which is sometimes responsible for allergies. Sourdough bread keeps longer than yeast-raised bread, because the acidity provided by sourdough slows down the “retrogradation” of starch. Through this spontaneous phenomenon, the starch tends to return to its original structure, promoting the exchange of moisture between the bread and the surrounding environment. Retrogradation is largely responsible for staling. The baker’s art lies in using techniques that slow down this natural mechanism.