Yeasts, like mushrooms are part of the fungi family.  Yeasts have been part of our culinary culture for millennia, and play a role in many of the foods we enjoy, from bread to yogurt, cheese, wine and pickles. Nutritional yeast (pure strains of Saccharomyces cerevisiae) is cultivated specifically for its nutritional value and has high quality protein, vitamins and minerals. It has no leavening power.After the yeast are grown, cultivated and fermented, the yeast are harvested, thoroughly washed and cleaned, and dried on roller drum dryers.