> Ketchup was not invented in the United States. It began as a fermented fish sauce — sans tomatoes — in early China. British sailors bought the sauce, called ke-tsiap or ke-tchup by 17th-century Chinese and Indonesian traders, to provide relief from the dry and mundane hardtack and salt pork they ate aboard ship. Over the next couple of centuries, ketchup spread throughout the British Empire, traveling around the world with the navy.
The (surely apocryphal) origin story I heard for Worcestershire sauce was that it was a (failed) attempt to replicate an Indian tamarind chutney, which was abandonded, left to ferment in barrels, and rediscovered.
I've been eating ketchup for 40 years. I've never kept it in the fridge. I hate putting a thick cold sauce on hot food. I've always assumed that the vinegar and preservatives were enough to make it last for the short time a bottle of ketchup lasts in my house.
Same, no problems yet. A hypothesis I found while looking into it: shelf life of condiments nowadays might be less than it used to be due to manufacturers cutting sugar and salt.
> Is there a difference between ketchup and catsup?
> No. (Rest easy, Mr. Burns.) Both are names for a sauce that once was made using a variety of ingredients, including mushrooms and walnuts, and is now primarily made using tomatoes.[0]
I once made my own ketchup. After nearly 2 hours of work the result tasted pretty much like a really cheap and not very good commercial ketchup. Before you add sugar and vinegar, it tastes like a delicious Indian tomato sauce, though.
Supposedly Asian fish sauces are similar to both Worcestershire sauce https://en.wikipedia.org/wiki/Worcestershire_sauce and the ancient Roman garum https://en.wikipedia.org/wiki/Garum . Some say that Colatura di alici https://en.wikipedia.org/wiki/Colatura_di_Alici from Cetara in Italy is the best of them all.