Governo is a winemaking technique reportedly invented in Tuscany in the 14th century to help complete fermentation and stabilize the wine.
The technique involves saving a batch of harvested grapes and allowing them to partially dry.
[1] From there, the must can be fermented dry or stopped with the wine having a higher level of residual sugar.
The process was widely used in the Chianti zones until the advent of temperature controlled fermentation tanks.
With very acidic grapes like Sangiovese this process will temper some of the harshness and volatility in the wine.