Wine Word of the Week: Sulfur dioxide

By Kori ~ August 13th, 2009.

Wine Word of the WeekThis week’s Wine Word of the Week is sulfur dioxide.

Official definition from Jancis Robinson’s The Oxford Companion to Wine:
Sulfur dioxide, or SO2, formed when elemental sulfur is burned in air, is the chemical compound most widely used by the winemaker, principally as a preservative and a disinfectant. ….

Sulfur dioxide reacts with oxygen and so prevents oxidation, which has undesirable effects on the color and flavor of wine. ….

The disadvantage of using sulfur dioxide is that its aroma can be quite unpleasant even at fairly low concentrations, especially to some particularly sensitive tasters.

Layman’s terms from Kori:
Sulfur dioxide, or SO2, is important in winemaking because it prevents spoilage, browning, and oxidation. However, an aroma of burnt matches in a wine is an indication of too much SO2 and is considered a wine fault.

Filed under: Wine Word of the Week

Reader's Comments

  1. Online Wine Auctions | August 17th, 2009 at 5:56 am

    Ahuh, so that explains the old ‘burnt matches’ smell!
    Thanks guys.

  2. Kori | August 18th, 2009 at 1:57 pm

    Glad we could help. Cheers!