Question:
Is brewer’s yeast chametz? Do I have to sell it? I try to avoid selling chametz gamur.
Thank you so much! Pesach kasher v’samech!
Answer:
Brewer’s yeast is a fermented barley, and therefore by definition chametz. All products that contain it must be removed for Pesach.
Note that the se’or the Torah prohibits is what is known as “sourdough” – yeast made from a bread base. This is of course strictly forbidden as chametz gamur.
Other forms of yeast are chemically made, and are not chametz.
Best wishes.