Ascorbic acid

Ascorbic acid meaning in winemaking

Ascorbic acid, commonly known as vitamin C, is a powerful antioxidant additive used in winemaking to prevent the oxidation of grape must and wine. This water-soluble compound effectively scavenges oxygen and free radicals that can cause browning, off-flavors, and loss of fresh fruit characteristics in wine. Winemakers typically add ascorbic acid at concentrations of 50-250 mg/L during crushing, pressing, or bottling stages. It works synergistically with sulfur dioxide (SO₂) to provide enhanced antioxidant protection, often allowing for reduced sulfite usage. Ascorbic acid is particularly valuable when processing white grapes and delicate varietals prone to oxidation, such as Sauvignon Blanc and Pinot Grigio. The compound helps preserve the wine’s natural color, maintains volatile aromatic compounds, and extends shelf life. Unlike sulfites, ascorbic acid is generally well-tolerated by consumers and doesn’t require labeling in most jurisdictions. However, it must be used carefully as excessive amounts can cause reductive off-flavors or interact negatively with certain wine components. In Argentine winemaking, ascorbic acid is commonly employed in high-altitude vineyards where intense UV radiation and temperature fluctuations increase oxidation risks during harvest and processing.

FAQs

Why is vitamin C (ascorbic acid) used in wine?

Ascorbic acid, commonly known as vitamin C, acts as a powerful antioxidant in wine. It scavenges oxygen to prevent browning and preserve fresh fruit flavors, which is especially useful for delicate white wines.

When does ascorbic acid wine addition occur?

Winemakers typically add ascorbic acid during the crushing, pressing, or bottling stages. It is usually added alongside sulfur dioxide (SO₂) for enhanced protection against oxidation.