Wikipedia apparently spells it 'ketchup' too (both spellings are equally familiar to me, but the older 'catchup' is one that I find jarring), and says that nowadays commercially produced catsup is limited to only tomato, mushroom, and banana varieties. Eventually I should try to dig up recipes for other catsups/ketchups in old cookbooks and try to make them. Someday.
In the bottle, tomato ketchup changes colour pretty darned slowly (I've seen it happen in the fridge, because I use it up so very slowly); the change is much more pronounced in those wee packets, and I've learned to look at the colour inside when I open them, before squirting them on my plate, just in case.
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Also, I've never seen ketchup change color unless it's left out to dry out.
(no subject)
In the bottle, tomato ketchup changes colour pretty darned slowly (I've seen it happen in the fridge, because I use it up so very slowly); the change is much more pronounced in those wee packets, and I've learned to look at the colour inside when I open them, before squirting them on my plate, just in case.
(no subject)