Arak is usually mixed in approximately 1/3 arak and 2/3 water in a traditional Levantine water vessel called "Ibrik", in Arabic "إبريق"; then the mixture is poured in small ice filled cups, like in the picture. This dilution causes the clear liquor to turn a translucent milky-white color; this is because anethole, the essential oil of anise, is soluble in alcohol but not in water. This results in an emulsion, whose fine droplets scatter the light and turn the liquid translucent, a phenomenon known as louching.