Question:
Shalom, why in Pesach can not eat bread with yeast and wine can?
Answer:
You are asking an important question, and the answer is because this is what G-D has commanded us. It is written numerous times in the bible (See Exodus 12 15, 19,20, 13-7) that we are not to eat bread which has risen and started to ferment (called chametz) even if no yeast was added to it. In fact not only are we strictly forbidden to eat chametz, we may also not have any chametz in our possession during the Passover holiday. it is not an issue of fermenting, rather an issue of the bread raising and becoming chometz.
Best wishes
