Acorn "coffee" was drunk in South by Scarlett O'Hara and her Confederate compatriots. For Turks, acorns yielded raccabout. Under pressure of World War II, Germans drank Eichel kaffee. Hitler deserved it, opined physician and author Richard Gordon. And according to the ineffable Pamela Michaels, the English used oak leaves to make wine.
But before these more recent times, acorns played an important in early gastronomic human history. Neolithic lake dwellers in Switzerland collected acorns ashore, losing some of them in the mud below their homes to be preserved to modern times. Lower classes as far apart as ancient Greece and Japan fed on the nutritious nuts. Roman researcher Pliny the Elder wrote that acorn flour could make bread. He neglected to report if he himself ate it. In California before the arrival of white colonists, Native Americans positively thrived on acorns. Spreading the harvest over several species, they formed a staple diet for a population estimated to have been in the tens if not hundreds of thousands.