The most well-known preservative used in wine production is potassium metabisulfite or commonly Potassium Metabisulfite.

It works as follows:
a) protects the must and grape pulp from oxidations (antioxidant action)
b) acts selectively on wine bacteria (acetic, lactic, pyruvic, etc.) inhibiting their action, without hindering the action of yeasts, thus making alcoholic fermentation safer and more certain
c) stabilizes the color in whites to yellow-green shades, and intensifies the color in reds
d) prevents various hazes in wine from appearing easily, whether of enzymatic or other origin, e.g., iron
e) preserves the wine either in the barrel or in the bottle