Когда родился профессор кислых щей

The article discusses the meaning, use and history of the expression «the professor of sour cabbage soup». It is steadily used in the modern Russian language, but the dating of its origin is not clarified. The comparison of various vocabulary materials allows drawing a conclusion that it became actively used only in the second half of the twentieth century. This dating makes it possible to take a different view of the initial semantics of its components.