The ancient Spartanmelas zomos (μέλας ζωμός), or black soup / black broth, was a staplesoup made of boiled pigs' legs, blood, salt and vinegar. It is thought that the vinegar was used as an emulsifier to keep the blood from clotting during the cooking process. The armies of Sparta mainly ate this. It was not a delicacy, but used for sustenance.
According to legend, a man from Sybaris, a city in southern Italy infamous for its luxury and gluttony (which gave rise to the word sybarite), after tasting the Spartans' black soup remarked with disgust, "Now I know why the Spartans do not fear death". In another story, it is said that Dionysius, the tyrant of Syracuse, for the sake of this bought a slave who had been a Spartan cook, and ordered him to prepare the broth for him, sparing no expense; but when the king tasted it he spat it out in disgust; whereupon the cook said, "Your Majesty, it is necessary to have exercised in the Spartan manner, and to have bathed in the Eurotas, in order to relish this broth."
No recipe for the Spartan black soup has survived, but blood soups are still eaten in various countries today, such as Italy, France and also Serbia.
Clauss, Manfred (1983). Sparta. Eine Einführung in seine Geschichte und Zivilisation (Sparta. An Introduction to its History and Civilisation) (in German). C.H. Beck, München (Beck'sche Elementarbücher). p. 166. ISBN3-406-09476-7.