Ketchup is the ultimate American condiment—burgers, fries, diner tables, childhood. But if you time-traveled to 1700 and asked for ketchup, you wouldn’t get tomatoes.
You’d get a dark, pungent liquid that smelled like the ocean had opinions.
Here is what is actually happening.
British sailors in Southeast Asia found a Chinese sauce called Ke-Tsiap—a fermented, salty, umami liquid made from fish entrails, brine, and spices. It was shelf-stable and valuable. They loved it, brought it home, and then spent a century failing to replicate it properly. For years, "ketchup" in Britain meant anything savory and brown—walnuts, mushrooms, oysters—basically soy sauce made from whatever they found in the yard.
When tomatoes finally entered the chat in the 1800s, they had a fatal flaw: they fermented too fast. Early tomato ketchup bottles exploded or turned to vinegar. The modern red stuff didn't win because of flavor; it won because Heinz solved safety. They used ripe tomatoes (high pectin) and cranked the vinegar and sugar so high that the sauce became self-preserving. That preservation hack is why ketchup is sweet, sour, and universally addicting today.
Do This Tonight (Quick Homemade Ketchup)
If your recipe site has any “flex,” it’s this: a ketchup that tastes like tomatoes instead of corn syrup vibes.
- The Base: Sweat 1 diced onion and 2 cloves garlic. Add 1 tbsp tomato paste and cook 60 seconds.
- The Simmer: Add one 28oz can crushed tomatoes, 1/3 cup apple cider vinegar, 2-4 tbsp brown sugar, and 1 tsp salt. Simmer 25-35 minutes.
- The Secret: Blend smooth. Then add a splash of fish sauce. It’s the ghost of Ke-Tsiap, and it makes the flavor 3D.
This is history in a bottle.