Sulfur dioxide (SO2) is an additive added in small amounts to wine as an antioxidant. It is also called sulfite.
It is a substance that is used to prevent oxidation and spoilage, as well as to stop alcoholic fermentation.
Producers have a variety of opinions regarding the addition of sulfurous acid, such as "If we don't use it, the quality of the wine cannot be maintained, so it should be used appropriately," or "It's better not to use it as much as possible." In recent years, the overall trend around the world has been for more and more producers to reduce their use.
By the way, sulfites are not artificially added; they are naturally produced in small amounts in wine by the action of yeast during alcoholic fermentation. Therefore, there is almost no wine that is completely free of sulfites.