Final answer:
Passerillage is a technique used in Sauternes that concentrates the sugar in grapes by allowing them to partially dry on the vine. It contributes to the development of noble rot, enhancing the wine's complexity and flavors. The result is a sweet wine with a distinct balance of acidity and full-bodied taste.
Step-by-step explanation:
In Sauternes, a technique known as passerillage is used, which involves leaving the grapes on the vine to partially dry out, developing a higher concentration of sugar. This process is essential in the creation of Sauternes wine and significantly contributes to its unique character. When passerillage occurs, water evaporates from the grape while the sugar and other solids remain. This leads to a greater concentration of sugar, which is crucial for producing the sweet flavor profile Sauternes is known for.
Additionally, passerillage can promote the development of Botrytis cinerea, also known as noble rot, which adds complexity, richness, and unique flavors to the wine. The outcome of this process is a lusciously sweet wine with balanced acidity and a full body, often with flavors of honey, nuts, and dried apricots. Only a specific percentage of the grapes undergo passerillage to ensure the wine achieves the desired balance and quality.