Black Vinegar Sauce

Black vinegar has the color of molasses. The last time I saw the real thing was in a cask belonging to an elderly cousin of mine; her mother had made it in 1927. Cousin Mary used that vintage vinegar like a precious elixir in mincemeats and sour fricassees, as well as multitudes of sweet-and-sour dressings during the hot months of the year. Once very much a part of our historical cookery, black vinegar has now more or less disappeared, even though excellent old recipes for it abound. It is