What is the main purpose of the flor yeast in Fino Sherry production?

The main purpose of the flor yeast in Fino Sherry production is to protect the wine from oxidation. Flor yeast forms a protective layer on the surface of the wine while it is aging in barrel, which significantly limits its exposure to oxygen. This anaerobic environment is crucial for developing the unique characteristics of Fino Sherry, including its delicate flavors and aromas, as well as its pale color. The flor also contributes to the wine’s fresh and nutty notes, while maintaining its dryness.

While enhancing sweetness, adding acidity, and clarifying the wine are important processes in winemaking, they are not the primary functions of flor yeast specifically in the context of Fino Sherry production. Flor yeast plays a critical role in establishing the distinctive profile that defines this style of Sherry, safeguarding it against oxidation and allowing it to develop its unique qualities over time.