Ketchup’s origins are found in Asia, and its adaptation into the thing that resembles our thick, modern-day ketchup began in early modern Britain….It’s likely that Britons encountered this tasty sauce – a thin, black-brown liquid that was either a type of fish sauce or a type of soy sauce – during acts of travel and colonization…

But ketchup was either so popular, so hard to get, or so expensive, that early modern British people soon started trying to make their own…In their quest to replicate the umami flavor found in soy- or fish-based Chinese or Malay sauces, Britons turned to a variety of ingredients: mushrooms, anchovies, oysters, walnuts, and even horseradish…

Most early modern British ketchups were heavily flavored, seasoned, and spiced….It wasn’t until the nineteenth century that Anglo-Americans began to incorporate tomatoes into their ketchup…

See “Colonizing Condiments: A (Very) Short History of Ketchup” by Amanda Herbert on The Recipes Project website (2019)