Brewer’s yeast is a live yeast used for brewing beer that is killed and turned into a dietary supplement. Nutritional yeast is a deactivated yeast grown solely for its nutritional content.

Brewer’s yeast grows on malted barley or other grains used for beer. Once the beer is complete, the yeast is separated and dried. This process deactivates or “kills” the yeast cells.

Nutritional yeast is “primary grown,” which means it’s created specifically for the purpose of producing a dietary supplement. Common growing mediums are beet or cane sugar molasses.

Brewer’s yeast is high in certain B vitamins, including thiamine, riboflavin, niacin, and folic acid, and protein and fiber. Both types contain magnesium, but brewer’s yeast has more trace minerals.

Nutritional yeast is also high in some B vitamins, protein, and fiber. It also contains vitamin b-12, an essential vitamin that vegans can’t get in their diet unless they take a supplement.