What is Metabisulphite?

Metabisulphite refers to a chemical compound that is commonly available in two forms: sodium metabisulphite (Na₂S₂O₅) and potassium metabisulphite (K₂S₂O₅).

These compounds are salts of metabisulphurous acid and are widely used as preservatives and antioxidants in food and beverages, as well as for sterilizing equipment in winemaking, and in various industrial processes.

• Chemical formula (sodium metabisulphite): Na₂S₂O₅
• Chemical formula (potassium metabisulphite): K₂S₂O₅
• Appearance: White or yellowish crystalline powder
• Main uses: Preservative, antioxidant, sterilizing agent

Metabisulphites release sulphur dioxide (SO₂) when dissolved in water, which helps prevent microbial growth and oxidation.