Sweet wine is a type of wine that contains a higher amount of residual sugar, which is the natural grape sugars left in the wine after the fermentation process is complete. The sweetness in sweet wines can result from several factors, such as the grape variety used, the winemaking techniques employed, or the addition of sugar after fermentation.

During the winemaking process, yeast consumes grape sugars and converts them into alcohol and carbon dioxide through fermentation. In the case of sweet wines, fermentation is stopped before all the sugars are converted into alcohol, leaving some residual sweetness in the final product.

Sweet wines come in various styles, ranging from lightly sweet to intensely sweet. Examples of sweet wine styles include late harvest wines, ice wines, noble rot affected wines (such as Sauternes), and some dessert wines. These wines are often enjoyed as aperitifs, dessert wines, or paired with foods that complement their sweetness, such as certain cheeses or desserts.