If you haven't heard of the spice, no worries. Basically, nutritional yeast is deactivated yeast made from cane or beet sugar. It comes dried in light yellow flakes or a tan powder, and is known for its savory taste as a cheese alternative, its high B vitamin content, and inclusion in many plant-based recipes, from sauces to vegan tacos. When used to coat spuds before baking them in the oven, nutritional yeast imparts a balanced, savory, nutty flavor.