Sodium metabisulphite is a versatile home brewing chemical used to sterilise equipment, protect finished wine and cider from oxidation and spoilage bacteria, and remove chlorine from brewing water.
For sterilising, mix around 1 teaspoon per litre of water, coat all surfaces, then rinse thoroughly. For stabilising wine, use alongside a Campden tablet. Read our full guide: Sodium Metabisulphite: What It Is & How to Use It.