Grapes, Unripe

Unripe grapes (ghureh in Persian), used as a souring agent in many Iranian dishes, are sold at Persian groceries in various forms: fresh in season, whole frozen and canned; as unripe grape juice (abghureh), also known as verjuice; and as powdered unripe grapes (garde ghureh). Although the taste will not be quite the same, you can substitute fresh lime juice for them in recipes: Allow 4 tablespoons of lime juice per 1 ½ cups unripe grapes, 1 cup grape juice or 1 teaspoon of powder.