From dusk on April 10 to dusk on April 18, the feast of unleavened bread, Passover, commemorates the Israelites’ liberation from Egyptian slavery. While grain yeasts are forbidden throughout the festival, grape yeasts are lawful, making kosher wines, crafted crush-to-bottle by observant Jews, a staple. In fact, at the opening banquet, the Passover Seder, it is a Rabbinic requirement for adults to imbibe four cups of wine, representing sanctification, deliverance, redemption and hope.