Baker's yeastBaker's yeast is the common name for the strains of yeast commonly used in baking bread and other bakery products, serving as a leavening agent which causes the bread to rise (expand and become lighter and softer) by converting the fermentable sugars present in the dough into carbon dioxide and ethanol. Baker's yeast is of the species Saccharomyces cerevisiae, and is the same species (but a different strain) as the kind commonly used in alcoholic fermentation, which is called brewer's yeast or the deactivated form nutritional yeast.
Yeast flocculationYeast flocculation typically refers to the clumping together (flocculation) of brewing yeast once the sugar in a wort has been fermented into beer. In the case of "top-fermenting" ale yeast (Saccharomyces cerevisiae), the yeast creates a krausen, or barm on the top of the liquid, unlike "bottom-fermenting" lager yeast (Saccharomyces pastorianus) where the yeast falls to the bottom of the brewing vessel. Cell aggregation occurs throughout microbiology, in bacteria, filamentous algae, fungi and yeast.
