Fermentation is a naturally occurring process in which the yeast found in the grapes converts the natural sugars into alcohol. The more sugar the grape contains, the higher the level of alcohol.
There are seven basic categories of wine:
- Red Wine: Made from dark skinned grapes when the skins remain with the juice during fermentation
- White Wine: Made from grapes with the (usually pale) skins removed before fermentation
- Rosé Wine: Made from dark skinned grapes when skins have been allowed brief contact with the juice during fermentation. Obviously, the longer the contact, the deeper the color will be
- Sparkling Wine: Wines which contain small bubbles of carbon-dioxide, either as a result of a secondary natural fermentation or through post-fermentation injection. The most famous come from the Champagne region of North-East France
- Distilled Wine: Brandy is made from fermented wines which have been distilled to 35 -60% alcohol and the name comes from the Dutch word brandewijn —‘burnt wine’. The best known brandies are Cognac and Armagnac, two regions in South-West France
- Fortified Wine: Made from fermented wine to which some brandy has been added, raising the alcohol level to about 18-20%. The most famous fortified wines are from Jerez (Sherry) in Southern Spain and Porto (Port) in Northern Portugal.
- Raisinated Wine: Rather than fermenting the juice of the freshly picked fruit, the grapes are allowed to dry in the sun, becoming more like raisins before they are crushed and allowed to ferment. This process, which is called appassimento in Italian, concentrates the sugars and thus results in a far higher alcohol level as well as a sweeter wine. Historically all the best and most expensive wines used to be made this way.