Which varietal is referred to as "little sweet one" and has low acidity?

The varietal referred to as "little sweet one" is indeed Dolcetto. This name, which translates to "little sweet one" in Italian, reflects the grape's characteristic fruit profile that tends to exhibit softer, fruit-forward flavors, often with slight sweetness, particularly in its young forms.

Dolcetto wines are known for their low acidity, making them approachable and easy to drink, often with a rich, juicy character that can include flavors of black cherry, plum, and blackberry. This approachable nature makes Dolcetto a popular choice for casual drinking and pairs well with a variety of Italian dishes.

Other varietals, such as Barbera and Nebbiolo, have higher acidity levels and different flavor profiles that don't align with the description of being sweet or low in acidity. Moscato, while also being sweet, is primarily known as a white wine and is distinct from the red Dolcetto. Thus, the name "little sweet one" aptly captures Dolcetto's identity within the context of these options.