The grape, crowned king of the fruits. Image by author with the help of ChatGPT.

The Grape’s Reign: Why Wine Rules the Fermented Fruits

The chemistry behind an ancient choice

Long before anyone made wine, a remarkable thing happened that changed the course of a fruit and mankind, at least in a certain latitude to start with. Wild grapevines come in two sexes. A male vine makes pollen but no fruit, and a female vine makes fruit but needs a male nearby to pollinate it. Among these wild vines bearing small berries, a random series of reshuffling in their chromosomes turned a few into hermaphrodites [1, 2, 3]. A hermaphrodite is a living being that carries both sexes within one, so each flower makes its own pollen and its own fruit. Hence it can pollinate itself and bear fruit, and seed, without needing a partner. The switch lives in a short stretch of one chromosome, the sex region, which every vine carries in two copies. In a male vine, the male and female copies of that region swapped pieces, and the new copy carried the instructions for pollen and fruit together [1, 3]. Genetic studies have identified two different hermaphroditic haplotypes among cultivated grapevines, whose ancestral genetic lineages appear to predate domestication [3].

Inside a male vine, its male and female copies likely swapped pieces, and the new copy carried pollen on and fruit on together [1, 4]. Image by author with the help of ChatGPT.