The Ladies Best Companion; Or, a Golden Treasure for the Fair Sex (1800)
The original ketchup, or catchup, was not the sweet and tangy condiment we know today. The recipe above was the most common in the Georgian and Regency era, being more of a fish sauce than the vinegar based vegetable, nut, or fungi sauce it would turn into:
A Practical Treatise on the Manufacture of Vinegar and Acetates, Cider, and Fruit-wines; Preservation of Fruits and Vegetables by Canning and Evaporation (1889)