Ketchup
Ketchup (catsup) is produced from tomatoes with the addition of vinegar, sugar, and spices. It is used as a condiment and as a basis for other sauces.
Ketchup is famously a non-Newtonian, thixotropic (shear-thinning) fluid, thick under static conditions, then when agitated the viscosity is reduced, returning to the viscous state when static again. Its viscosity ranges from up to 50,000 cPs while static to around 5,000 cPs when agitated, with specific gravity about 1.13. It is acidic, with a pH ranging from 3.6 to 3.9.