What's the Difference Between Ketchup and Catsup?

Ketchup and catsup: You’ve heard both words, and probably even dipped a plate of French fries in a pile of each one. You didn’t notice a difference in taste, so what gives?

Ketchup and catsup are simply two different spellings for the same thing: a modern, Westernized version of a condiment that European traders were introduced to while visiting the Far East in the late 17th century. What exactly that condiment was, and where they found it, is a matter of a much wider debate.

It could have been ke-chiap, from China’s southern coastal Fujian region. Or it could have been kicap, a Malay word borrowed from the Cantonese dialect of Chinese from Indonesia, also spelled kecap and ketjap, both of which are sauces based on brined or pickled fish or shellfish, herbs, and spices. Whatever it was, the Europeans liked it, and as early 1690, they brought it back home with them and began calling it catchup.

The early Western versions of the sauce—which, beginning in 1711, was sometimes called ketchup, another Anglicization of the Malay name popularized in the book An Account of Trade in India—were pretty faithful to the original Eastern ones, with one of the earliest recipes published in England (1727) calling for anchovies, shallots, vinegar, white wine, cloves, ginger, mace, nutmeg, pepper, and lemon peel. It wasn’t until almost a century later that tomatoes found their way into the sauce, in a recipe in an American cookbook published in 1801. In the meantime, another alternative spelling popped up, which was mentioned in a 1730 Jonathan Swift poem: "And, for our home-bred British cheer, Botargo [a fish roe-based relish], catsup, and caveer [caviar]."

The tomato-based version of ketchup quickly caught on in the U.S. during the first few decades of the 19th century. At first, it was made and locally sold by farmers, but by 1837 at least one company was producing and distributing it on a national scale. The H. J. Heinz Company, a name that’s synonymous with ketchup for most people today, was a relative latecomer to the game and didn’t produce a tomato-based ketchup until 1876. They originally referred to their product as catsup, but switched to ketchup in the 1880s to stand out. Eventually, ketchup became the standard spelling in the industry and among consumers, though you can still find catsup strongholds sprinkled across the U.S.

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A version of this story ran in 2012; it has been updated for 2023.