When dissolved in a solvent, sodium Metabisulphite is a granulated powder that releases sulphur dioxide. It's added to fresh juices in small amounts 24 hours before yeast is added. This will destroy any wild moulds and bacteria that might have been present on the fruit.

As an equipment sanitizer, sodium metabisulphite is often used in higher doses with water. It can be used to clean fermenting containers, hydrometers, bottles, hoses, and anything else made of glass, metal, plastic, or wood that comes into contact with your beer or wine.

Every gallon of liquor contains about 55 parts-per-million (p.p.m.) sulphur dioxide (SO2). Every gramme would give each gallon of liquid 175 p.p.m.
Sodium Metabisulphite is a powerful sterilising powder that, when dissolved in cold water (where it produces sulphur dioxide gas), prevents mould and bacteria from growing on all surfaces.

Brewing and winemaking supplies, as well as beer and wine bottles, are sterilised with this solution.
This product sterilises (sanitises) rather than cleans. This product should be used with clean equipment. 1 tablespoon per 5 litres of water is the recommended dosage. Allow the solution to come into contact with all surfaces. This dilution rate is only for equipment sterilisation.

Note: While sodium metabisulphite is used as a preservative in some cases, you should strictly adhere to food application laws and obtain details about its use from food safety authorities.

WARNING:

The sulphur fumes from this product can cause sensitivity in some people. In enclosed spaces, do not use this product. When working with diluted solutions, gloves are recommended.

TO PURIFY JUICE, ADD 1/16 teaspoon Sodium Metabisulfite per gallon of juice or 8 pounds of crushed fruit. Before applying to the juice, pre-dissolve in a small amount of water. Allow the juice to breathe for 24 hours in an open container before adding the yeast. Dosage should be doubled for overripe and possibly mouldy fruits.

ALL EQUIPMENT SHOULD BE Washed WITH SOAPY WATER PRIOR TO SANITIZATION. For each gallon of water, dissolve 1 teaspoon of sodium bisulfite. Add 1/2 teaspoon of citric acid as well. Put 2 to 3 inches of solution in the bottom of fermentation vessels to sanitise them. Enable the gases from the solution to permeate the inside walls by sealing the vessel airtight for 20 minutes.
You can also put in the vessel other equipment such as hoses, hydrometer, air-locks, rubber stoppers to be sanitized at the same time.

TO Retain the color and taste of the BEER OR WINE during BOTTLING: Add 1/16 teaspoon per gallon of beer or wine. Second, dissolve in a small amount of wine. To prevent re-fermentation, potassium sorbate is also recommended at this time. After adding the ingredients, bottle them right away.