Pesto became a staple in the Ligurian culinary tradition, with each family often featuring its own pesto recipe (with slight differences to the traditional ingredients). This is the main reason why pesto recipes often differ from each other. In 1944, "The New York Times" mentioned an imported canned pesto paste. In 1946, "Sunset" magazine published a pesto recipe by Angelo Pellegrini. Pesto did not become popular in North America until the 1980s and 1990s. Pesto is traditionally prepared in a marble mortar with a wooden pestle. First, garlic and pine nuts are placed in the mortar and reduced to a cream,
Pesto through a circular motion of a wooden pestle. This same Latin root, through Old French, also gave rise to the English noun "pestle". Strictly speaking, "pesto" is a generic term for anything that is made by pounding; that is why the word is used for several pestos in Italy. Nonetheless, "pesto alla genovese" ("Genoese pesto") remains the most popular pesto in Italy and the rest of the world. Pesto is thought to have two predecessors in ancient times, going back as far as the Roman age. The ancient Romans used to eat a similar paste called moretum, which was made