Basil is the essential main ingredient in traditional Italian pesto alla genovese.
The classic sauce comes from Genoa in Liguria, northwestern Italy. Its name derives from the Genoese verb pestâ, meaning “to pound” or “crush,” referring to the traditional method of grinding ingredients with a wooden pestle in a marble mortar.
Traditional pesto alla genovese combines Genovese basil with garlic, pine nuts, Ligurian extra-virgin olive oil, and grated cheeses such as Parmesan and pecorino. The basil provides the sauce’s distinctive fresh, sweet, and slightly peppery aroma. Genovese basil has protected-designation status when grown according to specified rules in Liguria.
Modern recipes may use walnuts, different cheeses, or substitute herbs, and “pesto” can broadly describe many pounded sauces. Mint, oregano, and parsley can appear in variations, but they are not the defining herb of traditional pesto alla genovese. Basil’s use in the modern sauce is documented from the nineteenth century.