Ouzo it is generally considered poor form to drink ouzo "dry hammer" ("ξεροσφύρι", "xerosfýri", an idiomatic expression that means "drinking alcohol without eating anything") in Greece. The presence of food, especially fats or oils, in the upper digestive system prolongs the absorption of ethanol and ameliorates alcohol intoxication. Ouzo is not used in many mainstream cocktail drinks, although in Cyprus it does form the basis of a cocktail called an Ouzini. Ouzo is a clear liquid. However, when water or ice is added, ouzo turns a milky-white colour. This is because anethole, the essential oil of anise, is completely soluble in
Ouzo effect levels. Addition of a small amount of surfactant or the application of high shear rates (strong stirring) can stabilize the oil droplets. In a water-rich ouzo mixture the droplet coalescence is dramatically slowed without mechanical agitation, dispersing agents, or surfactants. It forms a stable homogeneous fluid dispersion by liquid-liquid nucleation. The size of the droplets has been measured by small-angle neutron scattering to be on the order of a micron. Using dynamic light scattering, Sitnikova et al. showed that the droplets of oil in the emulsion grow by Ostwald ripening, and that droplets do not coalesce. The Ostwald ripening rate