A range of additives which can be used to improve the overall flavour of home made wine.
Potassium metabisulphite, also known as potassium pyrosulfite, 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 disulphite and is chemically very similar to sodium metabisulphite, with which it is sometimes used interchangeably.
Potassium metabisulphite is generally preferred out of the two as it does not contribute sodium to the diet.
Potassium metabisulphite 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 colour and delicate flavours of wine.
The typical dosage is 1/4 tsp (1.2322304 milliliters) potassium metabisulphite per 5 gallons of must (yielding roughly 75 ppm of SO2) prior to fermentation; then 1/2 tsp per five-gallon bucket (150 ppm of SO2) at bottling. Most commercial wineries do not add more than 30ppm at bottling.
Winemaking equipment is sanitized by spraying with a 1% SO2 (2 tsp potassium metabisulphite per L) solution
When dissolved in water this releases sulphur dioxide which has many important properties in wine and beer making:-
It has antiseptic qualities which will stun, if not kill, the bacteria and wild yeasts in or on fruit.
It has antioxidant qualities which help prevent the effects of oxidation in beer, cider or wine.
It destroys the enzyme that causes enzymatic browning in juice, similar to what happens to an apple if it is sliced and exposed to the air.
Without sulphite in some form much wine would be brown or amber in colour, smell oxidized (or have a sherry-like aroma), and would probably be ruined by bacterial spoilage.
Beer makers will also appreciate that sulphite also removes chlorine from water and therefore reduces the chance of beer being tainted with TCP flavours.
We recommend Potassium Metabisulphite both for adding to wine and as a steriliser but Sodium Metabisulphite as a steriliser only as it does impart a significant aroma and flavour to the wine especially in the short term.
1Kg Pack size