Walnut liqueur, often referred to as nocino, is a dark, sweet, and richly flavored alcoholic beverage made from green walnuts. Traditionally, it originates from Italy, where unripe walnuts are steeped in alcohol with a mix of sugar, spices, and sometimes citrus zest. The result is a complex, aromatic liqueur that balances the bitterness of the walnuts with the sweetness of the added ingredients.

In the context of cocktails, walnut liqueur is often used as a versatile ingredient to add depth and a unique flavor profile. It pairs well with a variety of spirits, including whiskey, rum, and brandy, and can be used in both stirred and shaken cocktails. Its nutty and slightly spicy notes make it an excellent addition to seasonal drinks, particularly those enjoyed in the fall and winter months. Whether used as a primary flavor or a subtle accent, walnut liqueur brings a sophisticated richness to any cocktail.