Sweet dessert wines are usually produced with a little help from noble rots. Most dessert wines can be categorized into 5 styles: Sparkling, Light & Sweet, Rich & Sweet, Sweet Red and Fortified. Sweet wine is made with with extra sweet wine grapes. To make them sweeter the fermentation is stopped before the yeast turns all the grape sugar into alcohol. Among the other method to make a wine sweeter and stop the fermentation there is the addition of Brandy to the wine.
Other methods to produce sweet wines are the late harvest, which allows the grapes to hang on the vines longer in the season so they become even sweeter and raisinated, the Noble Rot, a type of spore as known as Botrytis Cynerea which adds a distinctive flavour of honey and ginger, the Straw Mat (passito) which allows the grapes to lay on straws mats to raisinate before being pressed and the Ice Wine, which occurs only in years when a vineyard freezes and the grapes are harvested and pressed while still frozen. Some grapes are more suitable than others and the most known and used are: Muscat Blanc, Cabernet Sauvignon, Riesling, Trebbiano, Malvasia, Tokaji, and Sémillon.