Sulfur dioxide addition
/sʌlfər daɪˈɒksaɪd əˈdɪʃən/
Winemaking, Preservation, Chemistry, Safety, Regulations•Last updated April 28, 2025
Sulfur dioxide addition is the practice of adding sulfur dioxide (SO2) to wine to preserve its quality and prevent spoilage. It serves as an antioxidant and antimicrobial agent, protecting the wine from oxidation and unwanted microbial growth.
Examples
- Adding potassium metabisulfite to must before fermentation to control wild yeast.
- Using sulfur wicks to fumigate barrels to prevent spoilage.
- Adjusting free SO2 levels in wine before bottling to ensure stability during aging.
Etymology
The term 'sulfur dioxide' comes from the Latin 'sulfur' meaning 'sulfur' and 'dioxidum' meaning 'dioxide.' Its use in winemaking dates back to ancient Roman times for cleaning wine vessels, with systematic application becoming prevalent in the 19th and 20th centuries.
Usage Notes
Sulfur dioxide is added at various stages of winemaking, including crushing, fermentation, and bottling. The quantity added varies based on the wine's type, pH, and the winemaker's objectives.