On food and cooking the science and lore of the kitchen ( PDFDrive ) 1031

Guidelines for Working with Sourdoughs The key to successful baking with sourdough starters is to limit bacterial growth and acidification, and encourage a healthy yeast population In general, this means keeping sourdough starters relatively cool, and “refreshing” them frequently by adding new flour and water and aerating them vigorously Here are rules of thumb to keep in mind Frozen and Par-baked Doughs and Breads Bread dough can be frozen, thawed, and baked into bread, but freezing kills a large proportion of the yeast cells, which means less leavening power, a slower rise, and the spread of yeast chemicals that weaken gluten Sweet rich doughs turn out to freeze the best The best stage at which to freeze bread dough is after the dough has risen and baked for 70 to 80% of its usual baking time This frozen “par-baked” bread can be thawed and finished with just a few minutes in a hot oven Yeast survival is no longer important, because the yeast cells have done their leavening and are killed during the initial bake Both yeasts and bacteria grow fastest in liquid starters, which allow the microbes easier access to nutrients; in a semisolid dough they grow more slowly and require less frequent attention Because growing microbes consume nutrients rapidly, and produce acid and other growth-inhibiting substances, starters need to be divided and refreshed frequently, two or more times per day Adding new water and flour dilutes the accumulated acids and other growth inhibitors, and provides a fresh supply of food Aerating the starter — whisking a liquid one, or kneading a doughy one — supplies the oxygen that yeasts require to build cell membranes for new cells The more frequently the starter is divided and ... new water and flour dilutes the accumulated acids and other growth inhibitors, and provides a fresh supply of food Aerating the starter — whisking a liquid one, or kneading a doughy one — supplies the oxygen that yeasts... This frozen “par-baked” bread can be thawed and finished with just a few minutes in a hot oven Yeast survival is no longer important, because the yeast cells have done their leavening and are killed during the initial bake... Because growing microbes consume nutrients rapidly, and produce acid and other growth-inhibiting substances, starters need to be divided and refreshed frequently, two or more times per day Adding new water and flour dilutes the accumulated