Fruit is not the only source of natural sugar that will turn into alcohol without any help from anything except wild yeasts. Ripe fruit can, and will, ferment spontaneously as yeast arrive to grab the sugar in the fruit and flood the surroundings with alcohol to keep their rivals away.

If you walk through an untended apple orchard in the autumn, after the apples have fallen from the trees and been lying on the ground, the scent of cider will envelop you, as yeasts attack the rotting fruit. Right now, I’m in a Middle Eastern city where thousands of date palms line every road, and in the evening the strong smell of vinegar is on the warm air: this is because dates that have fallen to the ground have fermented, and then gone on to the next stage, where alcohol is converted by specialist bacteria into acetic acid.

In order of age, the first fermented drinks were fruit-based, followed by honey-based drinks – mead and its variants – next fermented sweet tree-sap drinks such as palm wine, and only fourth, beer.

More: Zythophile