Which grapes are used to produce the wines of the Orvieto DOC?

The Orvieto DOC, which is located in the Umbria region of Italy, primarily produces white wines that are well-regarded for their freshness and aromatic qualities. The main grape varieties used in the production of these wines are Trebbiano Toscano and Grechetto.

Trebbiano Toscano is known for its crisp acidity and ability to produce wines that are light and fruity, making it a foundational grape for many Italian white wines. Grechetto adds depth and complexity, often contributing notes of green apple, almond, and herbal nuances. The combination of these two varieties results in a harmonious balance, leading to wines that are both refreshing and flavorful, with good aging potential.

Other options listed, such as Tempranillo, Merlot, Chardonnay, Sauvignon Blanc, Cabernet Sauvignon, and Sangiovese, are associated with different wine regions or styles and do not play a significant role in the production of Orvieto DOC wines. This reinforces why Trebbiano Toscano and Grechetto are the correct answer, as they are specifically important to the identity and reputation of Orvieto wines.