What is the primary flavor in a traditional pesto sauce?

The primary flavor in a traditional pesto sauce is basil. Pesto, originating from the Liguria region of Italy, is known for its vibrant green color and distinct herbaceous flavor, which primarily comes from fresh basil leaves. The basil not only adds a unique aromatic quality but also serves as the foundational herb that characterizes the sauce. While garlic, olive oil, and Parmesan cheese are essential components of pesto and contribute to its overall flavor profile, none of these ingredients can overshadow the dominant taste provided by basil. Consequently, the essence of pesto is rooted in its use of abundant fresh basil, making it the primary flavor.