Sweet wines are all wines that have retained a significant portion of their sugar. Either the fermentation is stopped or it ceases spontaneously because the yeasts can not completely convert the large quantity of sugar into alcohol. The berries for late harvest wines are healthy with high maturity degrees. Noble sweet wines like Beerenauslese or the wines of the Sauternes in Bordeaux are produced from grapes, which are infested with the Botrytis noble rot and thus have a highly concentrated must. In southern regions of Europe, it is also common to dry ripe grapes to concentrate the sweetness of the must.