Yeasts are unicellular microorganisms.

They are responsible for transforming grape sugars into alcohol

Wine is a fermented food whose main fermentation is the alcoholic that yeasts carry out
When the alcoholic fermentation ends the yeasts die
With regard to yeasts, it has also been shown that the genera of Saccharomyces and Candida are those that culminate alcoholic fermentation, which differs from other studies conducted with massive sequencing in other grape varieties.
Alcoholic fermentation is produced by the action of yeasts; in some native (natural) cases, in others, added by the winemakers themselves, in a process that increases the temperature of the must producing carbonic gas