What Foods are Chametz?
The traditional interpretation of chametz is any flour of the five biblical species of grain: wheat, oats, spelt, barley, and rye, which has been combined with moisture and allowed to sit (and therefore ferment) before baking is completed. Note: Baking soda operates on a completely different principle from yeast, so it is neither se’or nor chametz. Wine and vinegar (other than grain vinegar) are not considered chametz, because they are not made from grain products.