One argument that is supposed to prove that the wine used by Jesus to institute the Lord’s Supper was just grape juice, is that leavening was forbidden to be used in the Passover, also called The Feast of Unleavened Bread. I read one claim that Jews were forbidden to partake of anything that contained any leaven ever.
A little bit of research shows that no leaven was allowed in the bread. That’s why it is called The Feast of Unleavened Bread. There was never a prohibition against wine (fermented grape juice), in fact it was and remains the norm for Passover celebrations. In fact, the term Jesus used, fruit of the vine, was used throughout the Mediterranean region to refer to fermented grape juice (aka wine) used for ceremonial purposes.
Passover is not The Feast of No Leavening — it is The Feast of Unleavened Bread.