Happy 1st of Aviv! Question: i have always purged my house of any leavening ingredient for the feast of unleavened bread. But, am i misunderstanding "leaven" is it only sourdough and poolish, and also cooked leavened bread we are to get rid of? Or am i right to get rid of it all: soups, baking soda, baking powder, baking yeast, nutritional yeast, etc? Thank you!