Yeasts, the man’s best friend

Abstract

1. Introduction In most cultures, bread making depends on a fermentation step. The flour leavening ability was, at first, most probably dependent on spontaneous fermentation. It became a controlled process by the maintenance of fresh innocula from one preparation to the next and this kind of environmental constraints eventually generated a particular type of yeast and bacteria biodiversity, adapted to ferment a certain brand of flour mixture, yielding specific organoleptic characteristics to the dough. Nowadays, although the baking industry generally uses commercially available strains of Saccharomyces cerevisiae for bread making, some types of bread are still prepared using dough carried over from previous makings as a starter. This trend decreased worldwide bread diversity and the cultural values associated, simultaneously increasing the dependence of local producers on world-scale yeast producers. Sustainability demands assessing yeast biodiversity, as well as devising simple and cheap methods for maintaining dough and multiply yeast.