What is the purpose of lees in the winemaking process?

The purpose of lees in the winemaking process primarily revolves around the complexity they can add to the wine. Lees are the sediment that forms during fermentation and consist of dead yeast cells, grape particles, and other solids. When winemakers choose to perform batonnage, which is the stirring of the wine with the lees, it can enhance the mouthfeel and contribute additional aromas and flavors that enrich the overall profile of the wine.

This technique is particularly beneficial in the production of certain styles of white wine, such as Chardonnay, where the interaction with the lees can create a creamier texture and add notes of bread or nuttiness. The decision to leave the wine in contact with the lees is part of a winemaker's strategy to shape the desired characteristics of the final product, illustrating the importance of this process in crafting complex and nuanced wines.

The other options do not accurately capture the role of lees. They do not provide color but rather influence flavor and texture. Lees are typically left in the wine after fermentation; removing them before fermentation would be counterproductive. Lastly, lees do not enhance sugar content; their role is much more centered on flavor and mouthfeel rather than increasing sweetness.