Which varietal is known for massive tannins and robust profiles of dark fruit and blackberry?

The varietal known for its massive tannins and robust profiles of dark fruit and blackberry is Nebbiolo. This grape is predominantly grown in the Piedmont region of Italy, where it produces some of the country's most esteemed wines, such as Barolo and Barbaresco.

Nebbiolo is characterized by its high acidity and significant tannin structure, which contributes to its ability to age well over time. The aromas and flavors often include notes of dark cherry, plum, and blackberry, complemented by floral characteristics and earthy undertones. The intense tannins create a firm mouthfeel, which pairs well with rich foods and further enhances the wine's aging potential.

In contrast, Barbera and Dolcetto are also important varietals from Piedmont but are generally lower in tannins and have a more fruit-forward profile, lacking the same depth and complexity associated with Nebbiolo. Moscato, on the other hand, is a sweet, aromatic varietal that is quite different in style and flavor profile compared to the bold, tannic characteristics of Nebbiolo. Hence, Nebbiolo stands out for its distinctive qualities that align with the description provided.