Green walnuts are the heart of nocillo. They have to be picked while still unripe, then cut on 23 June, the vigil of San Giovanni, a date that pins the drink to a single night on the calendar rather than to a vague season.
How the liqueur first appeared has slipped out of memory, yet the method that remains is described as almost ceremonial, a careful sequence held across the centuries more by habit than by a named inventor.
After the work of infusion comes patience: the liquid is left to rest for at least two months before anyone drinks it. What arrives in the glass is very dark, an old-style blend of about 40 degrees, with a strongly bitter taste and the character of a digestif. That wait is part of the appetite: colour deepens, the edge stays sharp, and the pour is meant for after the meal, not for haste.