Wine is fermented grape juice.
Fermentation transforms sugar into alcohol.
Vitis Vinifera is the most used grape vine species because it produces the higher quality wines and best aromas.
Grapes can be black or white.
Grape skins have wild yeast growing on them and it starts a spontaneous fermentation.
The cultured yeast is made in laboratory and the most common species is Saccharomyces Cerevisiae.
Commercial yeasts are flavor-active: they influence the outcome creating a "yeast bouquet".
While in the New World it is allowed to add acid during winemaking, it is forbidden in the Old World.
Many wines are not vegan and using fining agents such egg whites and gelatin is a common practice.