The New Family Receipt Book (1815)
Essentially a pickled walnut sauce that tastes “like a combination of Worcestershier and A1 Steak sauce” (https://honest-food.net/walnut-ketchup-recipe/).
Recipes vary on how long you should store before use, typically between three months to a year.
Ketchups were originally recipes that included egg whites, mushrooms, oysters, mussels, walnuts or other nuts. Now, we associated in USA with tomato ketchup.
