Dried Yeast Fermentate or Baker's yeast is the common name for the dried and preserved strains of yeast. It is widely used in as a leavening agent in baking. After some recent studies on its medicinal properties dried yeast extracts are increasingly being used in nutritional supplements. Study showed that dried yeast derived from the yeast Saccharomyces cerevisiae( a non-pathogenic yeast commonly used in baking and brewing) modulates immune function and supports cellular metabolism, which strengthens the immune system. It is normally administered in powdered form in capsules sizes of 500mg, taken one or two daily.