In music Sforzato means strained. In wine it translates to forced. In this case it refers to a passito style wine made in a similar way to Amarone, using Chiavennasca (Nebbiolo) in the Valtellina region in Lomabardy.
The grapes are picked, laid out on dry racks and left to slowly degydrate, losing as much as 40% of their weight, concentrating the sugars, acids, and, beyond in the grapes. When ready the winemaking process continues, as, the grapes are fermented and turned into a rich full bodied wine.