Chometz is one of the five grains: barley, wheat, rye, spelt and oats
mixed with water more than 18 minutes from the start of the mixing to
the end of baking. Wine does not contain any of the five grains.
Yeast is a one-celled plant. It is a levening agent not chometz in
itself. In Biblical times the yeast that fermented the grapes was not
an added ingredient, but came from the air.
Le-chaim.
Arlene Mathes-Scharf
ajms@kashrut.com