Petit Grain is an oil obtained from the leaves of various citrus trees. Predominantly the oil of the bitter orange (Citrus aurantium) is also called bitter orange. Mostly oils of sweet orange, mandarin and lemon are added. Petit Grain smells fresh, slightly tart, flowery-fruity. It is contained in "Kölnisch Wasser" in shower gels or shampoos, among other things.