What is 'decanting' used for in wine service?

Decanting is primarily used to separate wine from sediment and to aerate it. In the case of older red wines, sediment can develop during the aging process, and decanting allows for the careful transfer of the wine into another vessel, leaving the sediment behind in the original bottle. This helps to ensure that the drinker enjoys a clearer glass of wine without any gritty particles that could detract from the tasting experience.

Moreover, aeration is an important aspect of decanting as it increases the wine's exposure to oxygen. This process can enhance the wine's aromas and flavors, allowing it to open up and express its complexity more fully. As a result, decanting can improve the overall tasting experience by softening tannins and allowing the wine’s more subtle characteristics to emerge.

Options like chilling the wine quickly or enhancing its sweetness do not accurately reflect the primary purposes of decanting. Additionally, while decanting can have some effect on oxidation, its main function is not to prevent it but rather to facilitate the exposure of the wine to air during the service. Thus, the correct answer highlights the two essential roles of decanting in wine service: removing sediment and promoting aeration.