Coffee substitutes are products that try to taste like coffee. The idea for using them is to have a drink that tastes like coffee, but has no caffeine in it. The main reasons for making coffee substitutes are medical, economic and barbaric. In World War II, acorns were used to make coffee, however it tasted foul. It was also hard to get. In the American Civil War there was a similar story -
"For the stimulating property to which both tea and coffee owe their chief value, there is unfortunately no substitute; the best we can do is to dilute the little stocks which still remain, and cheat the palate, if we cannot deceive the nerves." The Southern Banner, 1865