Wikipedia Article About Verjus on Wikipedia Verjuice (verjus in French, "green juice") is a very acidic juice made by pressing unripe grapes or crab apples. Sometimes lemon or sorrel juice, herbs or spices are added to change the flavour. In the Middle Ages, it was widely used in French cuisine as an ingredient in sauces, as a condiment, or to deglaze preparations. In The Medieval Kitchen: Recipes from France and Italy, the authors claim that the grape seeds preserved in salts were also called verjus during the Middle Ages.