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
Flavour (particle physics) description of the flavour symmetry is described by a chiral group . If all quarks had non-zero but equal masses, then this chiral symmetry is broken to the "vector symmetry" of the "diagonal flavour group" , which applies the same transformation to both helicities of the quarks. This reduction of symmetry is a form of "explicit symmetry breaking". The amount of explicit symmetry breaking is controlled by the current quark masses in QCD. Even if quarks are massless, chiral flavour symmetry can be spontaneously broken if the vacuum of the theory contains a chiral condensate (as it does in low-energy