Which characteristic is not determined by the amount of glycerin in wine?

The characteristic that is not determined by the amount of glycerin in wine is alcohol content. Glycerin is a byproduct of fermentation and is often associated with the body's overall mouthfeel, sweetness, and texture of the wine, but it does not directly influence how much alcohol is present in the wine.

Alcohol content is determined primarily by the fermentation process itself, specifically the sugar content in the grapes and the yeasts used. While glycerin can affect the richness of color, smoothness of taste, and viscosity by contributing to the wine’s body and mouthfeel, it does not have any influence on the actual level of alcohol produced during fermentation. Thus, understanding the role of glycerin in wine can help with the appreciation of its texture and flavor profile, but it's essential to recognize that alcohol content is derived from different factors.