Sodium Metabisulfite is a common wine additive and sanitizer. It is traditionally used to inhibit wild yeasts and bacteria from fresh fruit prior to fermentation. It is also used after fermentation for its anti-oxidant and preservative effects. In white wines, it can also preserve color and prevent browning. The addition of sulphites is also claimed to improve the overall flavor of wine and preserve delicate qualities.
- 1/8 tsp per 1 gallon (3.79L) = approximately 100 ppm free SO2 (Sulfur Dioxide)
- 50 to 75ppm SO2 is commonly used to treat fresh fruit or juice musts
- 150ppm SO2 is commonly used to stabilize wine at the time of bottling