Ascorbic acid, also known as vitamin C, is a powerful antioxidant that is widely used in winemaking. It is a quick-acting and effective way to protect wine from oxidation, which can cause browning, spoilage, and off-flavors.
 
Ascorbic acid is particularly useful for white wines, which are more susceptible to oxidation than red wines. It can be added at any stage of winemaking, from crushing to bottling, to help preserve the wine's freshness and fruit character.