Original Receipt in 'The Cook and Housekeeper's Dictionary' by Mary Eaton (Eaton 1822);BLACK BUTTER. Boil a pound of moist sugar with three pounds of gooseberries, currants, raspberries, and cherries, till reduced to half the quantity. Put it into pots covered with brandy paper, and it will be found a pleasant sweetmeat.
The term seems to have been transferred in the early 19th Century to the French from of 'beurre noir' butter-and-parsley sauce.
Original Receipt from 'A Shilling Cookery for The People' by Alexis Soyer (Soyer 1845)425A. Black Butter.- Put two ounces of salt butter in a stew pan, set it on the fire; when it gets hot and brown add about twenty parsley leaves, half a teaspoonful of salt, a quarter of that of pepper, and two tablespoonfuls of vinegar, let the whole boil one minute and pour over any article suitable for this kind of sauce.