Potassium Metabisulphite (PMS) is used for sterilizing & stabilizing wines, or ciders. It is an antioxidant and bactericide that releases sulfur dioxide into wine must.
Use 1/4 teaspoon per 23 Litres to add 50 ppm (for stabilizing)
Methods for Adding Potassium Metabisulfite:
Before Fermentation:
Dissolve 1/3 teaspoon of potassium metabisulfite per 23L of juice to achieve a concentration of 50 ppm, and wait 24 hours before adding yeast.
During Racking:
After each transfer of wine off the sediment (racking), add 1/4 teaspoon per 23L of wine to maintain proper sulfite levels.
Before Bottling:
You may want to add another 1/4 of teaspoon of potassium metabisulfite again before bottling to further protect the wine from oxidation and spoilage. Typically this would be done if the wine has been "bulk ageing" for 2-3 months or more. If you do decide to make this step then wait at least 48hrs before bottling.
As a Sanitizer:
A solution of 2 teaspoons per gallon of warm water can be used to sanitize equipment and bottles.
*Always disolve in warm water prior to adding to must.
