Potassium Metabisulphite / Metabisulfite E224

POTASSIUM METABISULPHITE

Molecular formula: K₂O₅S₂

Synonyms: Potassium metabisulfite, Potassium pyrosulfite, Dipotassium disulphite, Dipotassium disulfite

Potassium metabisulfite is a white crystalline powder with a pungent sulfur odour. The main use for the chemical is as an antioxidant or chemical sterilant. It is a disulfite and is chemically very similar to sodium metabisulfite, with which it is sometimes used interchangeably. Potassium metabisulfite is generally preferred out of the two as it does not contribute sodium to the diet.

USES:

• Wine Making
  Potassium metabisulfite is a common wine or must additive, in which it forms sulfur dioxide gas (SO2). This both prevents most wild microorganisms from growing, and it acts as a potent antioxidant, protecting both the color and delicate flavors of wine;
• Beer 
  Potassium metabisulfite is sometimes used in the brewing industry to inhibit the growth of wild bacteria and fungi. This is called 'stabilizing'. It is also used to neutralize monochloramine from tap water. It is used both by homebrewers and commercial brewers alike;
• As a food additive E224;
• As a preservative (added to lemon juice, in some pickles etc.);
• In the textile industry for dyeing and cotton printing;
• It is a component of certain photographic developers and solutions used in photographic fixing;
• Used as a bleaching agent in the production of coconut cream.

Potassium metabisulfite causes skin irritation, serious eye irritation and may cause respiratory irritation.