At Passover, you may think it’s time to buy sweet kosher wines. But for centuries, most kosher wines were dry. The sweet stuff came along around 1900, when Eastern European Jews came to New York to escape the pogroms at home, and started looking for local grapes to make kosher wine. The nearest vineyards, in Upstate New York, grew mostly Concord grapes, which are tart for making wine. So they made the wines sweet. A decade ago, kosher wines made a major turn back toward dry.
Kosher means “correct,” or “proper.” It’s key the wine be pure for saying “kiddush,” or a blessing over wine at Seder.