Ketchup is everywhere—on fries, burgers, eggs, and hot dogs. But the red, sweet, tomato-based condiment we know today is barely two centuries old. The word "ketchup" is older, borrowed from Asian fish sauces that bore no resemblance to modern ketchup. The story of how fermented fish paste became America's favorite condiment is a journey through trade, colonialism, food science, and marketing genius.
The word "ketchup" likely derives from "kê-tsiap," a fermented fish sauce from southern China's Fujian province. Made from salted, fermented fish or shellfish, kê-tsiap was thin, salty, and intensely umami-rich—closer to modern fish sauce or soy sauce than to ketchup. It was used as a seasoning, not a condiment, adding savory depth to dishes.
British sailors encountered this sauce in the 17th century during trade expeditions to Southeast Asia. They loved its umami punch and tried to replicate it back home. But without access to the same fish and fermentation techniques, they improvised, creating "katchup" or "catsup" using local ingredients. These early British ketchups were nothing like the original—and nothing like what we eat today.
18th-century British cookbooks are full of ketchup recipes—none containing tomatoes. Mushroom ketchup was popular, made by salting mushrooms, letting them release liquid, then boiling that liquid with spices. Walnut ketchup used pickled walnuts. Oyster ketchup used oyster brine. These ketchups were thin, dark, and salty, used to add umami to stews, gravies, and meats. They were flavor enhancers, not table condiments.
The concept was clear: "ketchup" meant any thin, fermented or pickled sauce with intense savory flavor. The ingredient didn't matter—the function did. This is why "ketchup" became a category, not a specific recipe. And when tomatoes arrived in the picture, they were just another variation in a long line of experiments.
Tomatoes were native to the Americas, cultivated by indigenous peoples for millennia. But Europeans initially feared them as poisonous (they're part of the nightshade family, which includes deadly belladonna). By the early 1800s, Americans had overcome this fear and were growing tomatoes widely.
The first published tomato ketchup recipe appeared in 1812, in James Mease's cookbook "The Archives of Useful Knowledge." Mease's recipe used tomatoes, spices, and brandy, creating a thick, spiced sauce. Other cooks experimented, adding sugar, vinegar, and various spices. By the 1830s, tomato ketchup was becoming popular in American households, though it was still homemade and inconsistent.
Henry J. Heinz didn't invent tomato ketchup, but he perfected it. In 1876, Heinz released his version, and it changed everything. The innovation wasn't the recipe—it was preservation. Most commercial ketchups at the time used coal-tar preservatives or sodium benzoate, which were eventually deemed unsafe. Heinz used vinegar, sugar, and airtight glass bottles to create a shelf-stable product without harmful additives.
Heinz also standardized the recipe. While homemade ketchups varied wildly, Heinz ketchup tasted the same every time. This consistency, combined with clever marketing (the "57 Varieties" slogan, which Heinz admitted was arbitrary), made Heinz ketchup a household name. By the early 1900s, Heinz dominated the market, and "ketchup" meant tomato ketchup. All other variants—mushroom, walnut, oyster—faded into obscurity.
Heinz ketchup is famously thick and slow-pouring. This isn't accidental—it's chemistry. Ketchup is a non-Newtonian fluid, meaning its viscosity changes under stress. When sitting still, it's thick. When shaken or squeezed, it flows. This property comes from tomato pectin and the way sugar and vinegar interact with tomato solids.
Heinz capitalized on this by making thickness a selling point. "Slow ketchup" meant quality—real tomatoes, not watered-down substitutes. Competitors tried to match Heinz's thickness, and the race for the "perfect pour" became a defining feature of American ketchup. Today, ketchup's viscosity is so iconic that Heinz uses it in marketing: their famous "Anticipation" ads show ketchup slowly oozing from a bottle, building suspense.
Post-WWII, American influence spread globally, and ketchup followed. McDonald's, arriving in foreign markets in the 1970s, brought ketchup to places it had never been mainstream. By the 21st century, ketchup was ubiquitous—on tables from Tokyo to Buenos Aires. Regional variations emerged (banana ketchup in the Philippines, curry ketchup in Germany), but tomato ketchup remained the standard.
Ketchup's journey from fermented fish paste to tomato-based American icon took 300 years and crossed three continents. It's a story of adaptation, innovation, and the power of branding. Today's ketchup bears no resemblance to its Asian ancestors, yet the name persists, a linguistic fossil from a forgotten origin. And every time you squeeze that red bottle, you're participating in a culinary evolution that's still unfolding—one fry at a time.