French fortified wines

The concept of fortified wine is close to that of VDN (naturally sweet wine), which is the official designation used for this type of wine. These are wines made from red or white grapes and in which alcohol is added to stop fermentation in order to maintain residual sugar. This is called fortification. This should not be confused with mulled wine, which is prepared by fermentation of fruit juices concentrated by boiling.

We must give credit for fortification to Arnaud de Villeneuve, who managed to distill the wine. The stimulating effects of distilled alcohol inspired the name of water spirits. Continuing his studies, he discovered that the addition of the water spirits to wine stops the fermentation, preventing the wine and canned grape sugars from turning to vinegar.

Types of fortified wines
It is possible to distinguish:
Mistelle types of wine or liquor, where fortification is carried out before fermentation (i.e., early) with water spirits. These include, besides the Pineau des Charentes, the Floc de Gascogne and Macvin Jura that are developed with a brandy of the same origin as the grape. The Cartagena and Ratafia come from alcohol wine.

Some types of fortified wines are vin doux naturel, or VDN.  These include Rasteau, Banyuls, Rivesaltes, Porto, Maury or Muscat.  Here the fortification takes place during fermentation with pure alcohol. French law requires the use of a neutral alcohol.

Fortified wines, per se, are wines that have finished fermenting and where brandy is added, which is intended to raise the alcoholic strength, such as with sherry.  Madeira and Marsala may be the last two categories, depending on the type of wine sought.