In traditional Jain practice, nutritional yeast is not considered Jain-friendly and is best avoided.

Reason in simple terms:

• What it is: Nutritional yeast is a type of yeast (fungus) that is specially grown in huge quantity and then killed (deactivated) to use as a food ingredient.
• From a Jain view:

- Yeast is a one-sensed living being (ek‑indriya jiv). - Growing it and then deliberately killing countless such jiv for taste or nutrition goes against ahimsa. - This is the same basic reason most traditional Jains avoid all yeast/fermented products (like yeast‑bread, wine, etc.).

So even though it is vegan and “deactivated,” from a Jain dharmic point of view it still involves intentional cultivation and destruction of life, so it is generally treated as not Jain.

You can read a related discussion about yeast‑based products here: