The principle of wine production is simple:
Freshly harvested grapes are pressed. The juice (must) thusly won contains fermentable sugars and natural yeast. With their help or with the addition of supplemental yeast cultures, the process of fermentation starts. The fermentation process comes to a standstill when the sugars have been fermented away. The must has become wine.

This process of fermentation can be modified by diverse methods.

The most important variations exist in the production of red, white, rosé and sparkling wines.