Most wines – red or white – are fermented with the addition of yeast until all the sugar is converted into alcohol. This is how dry wines are made. However, if a sweeter wine is desired, three methods are available to give the beverage the desired sugar content: Interrupting fermentation: First, fermentation can be interrupted. To do this, the yeast must be removed from the liquid using a filter. This method is common and is used for many highly prized sweet wines. However, fermentation can also be interrupted by «poisoning» the yeast by adding sulfur dioxides or alcohol. Sprites are often mixed into the liquid for this purpose. This is how port wine from Portugal or Muscat wines from France (the Vins Doux Naturels), among others, are produced.
Dessert Sweetening: It is not permitted to use sugar to re-sweeten wines, though other liquids can be – unfermented grape juice (called sweet reserve), for example, which is often used to make German sweet wines.
Sugar concentration in the grapes: This method is used for the best sweet wines. To increase the sugar concentration in the grapes, they can be dried. Another possibility is noble rot, but freezing the grapes also increases the sugar content in the fruit. When the alcohol level of 15 percent by volume is reached in the subsequent fermentation process, the yeast dies; the sugar that is then not converted remains in the wine. After all the technical facts, we are happy to present you with our specific advice on the best sweet wines.