potassium metabisulfite

Potassium metabisulfite is an inorganic compound with the chemical formula K₂S₂O₅. It appears as a white crystalline powder or granules with a strong sulfur odor and is highly soluble in water. When dissolved in water, it releases sulfur dioxide (SO₂), which acts as a potent antioxidant and antimicrobial agent. Its primary uses are as a preservative and antioxidant in food and beverages—especially wine, beer, cider, juice—and as an equipment sanitizer for fermentation vessels. In winemaking and brewing industries it inhibits the growth of unwanted bacteria and fungi by releasing SO₂. Potassium metabisulfite is also used in the textile industry for bleaching fibers before dyeing; in photographic processing to prevent oxidation; for water treatment to neutralize chloramine; and occasionally as a gold precipitant from solution. As a food additive (E224), it prevents browning reactions (antibrowning agent) and extends shelf life by inhibiting microbial growth[1][5][6][8]. It may cause allergic reactions in sensitive individuals due to its release of SO₂.

Other names

potassium pyrosulfitepotassium disulfitedipotassium pyrosulfitepotassium pentaoxodisulfate