Typical usage is 1/4 to 1/2 teaspoon in 5-6 gallons of wine 24 hours prior to adding yeast. Similar amounts are used when racking and also prior to bottling. This small amount of sulfite goes a long way in preventing spoilage due to wild yeast or bacterial contamination.
Packaged in convenient, resealable, reusable and recyclable jars.
Also spelled metabisulfite.