The yeast used by brewers and bakers is called Saccharomyces cerevisiae, which uses sugar to produce carbon dioxide and alcohol. Flavoursome compounds are also produced. This single-cell fungus is rich in nutrients, especially water-soluble vitamins, like thiamin and folic acid, and some trace elements, like zinc and copper. The yeast contributes to the nutritional quality of a product like bread or beer. Just the name of this ingredient will most likely cause you to instantaneously dismiss it. Nutritional yeast doesn't sound like something you want to willingly eat; and it doesn't sound like it could possibly contribute to a tasty meal. But despite your first reaction to this little known ingredient (outside of the vegetarian and vegan world, that is), you should know about nutritional yeast. Trust us, you'll want to buy it and eat it, and you'll most likely love it. Nutritional yeast is an excellent source of protein, containing essential amino acids; it's full of vitamins, especially B-complex vitamins (and is often times fortified with vitamin B-12), and it's low in fat and sodium.