Ketchup

Ketchup is a thick, sweet and tangy sauce, now usually made from tomatoes. The original ketchup was not made from tomatoes at all: the word probably comes from a fermented fish sauce from southern China and South-east Asia, and early English ketchups were made from mushrooms, walnuts or oysters.^[1]

In the 1830s, tomato ketchup was sold as medicine in the United States. An American physician promoted tomatoes as a cure for indigestion and other complaints, and before long tomato pills and extracts were on sale. The medicine craze collapsed within a few years. The ketchup stayed, and has never once claimed to cure anything since.

Pouring

Ketchup is a non-Newtonian fluid: it is thick and almost solid when still, and becomes runny when it is shaken, squeezed or tapped. This is why ketchup will not come out of a glass bottle at all, and then comes out all at once.^[2] It is the only sauce that obeys physics only when nobody is looking.

• Bottle upright: no ketchup.
• Bottle upside down: no ketchup.
• Bottle tapped: no ketchup.
• Bottle tapped once more: all the ketchup.

Variants

Mushroom ketchup is still made in Britain, and is dark brown and thin. People who expect tomato ketchup and get mushroom ketchup are reported to look at it for a long time before deciding not to say anything.

See also

• Tomato – its main ingredient now
• Red – its colour
• List of things that are sticky – a candidate

References

1. Sauce, S. (1999). Not Always Tomato. Condiment Press.
2. Shear, T. (2006). “Tap It Once More”. Fluids at Dinner 1: 1.
3. Pill, P. (1837/2004). Take Two Tomatoes. Fictional reprint.