Which factor primarily influences a wine's sweetness?

The primary factor influencing a wine's sweetness is the presence of residual sugar. Residual sugar refers to the amount of natural sugars that remain in the wine after fermentation has completed. During this process, yeast converts sugars from the grape juice into alcohol, but if the fermentation is stopped before all the sugars are converted, some sugar will remain, leading to a sweeter taste.

Understanding residual sugar is crucial because it directly correlates to the perceived sweetness of the wine. Wines with higher residual sugar will taste sweeter, whereas those with little to no residual sugar will be perceived as dry. This factor is fundamental for winemakers as it allows them to create different styles of wine, from dry to sweet, based on how they manage the fermentation process.

While other factors like oak aging and alcohol content can influence the overall flavor profile of a wine, they do not significantly contribute to its sweetness. Oak aging can add complexity and flavors such as vanilla and spice, but it does not add sweetness. Similarly, while alcohol content can affect the richness and body of the wine, it does not determine the sweetness level. Tannin levels, which are associated with the astringency and structure of the wine, also do not influence sweetness. Hence, residual sugar stands out as the primary