II.2.1.2 Sulphiting

Classification :

• Sulphur dioxide: additive
• Ammonium hydrogen sulphite: additive
• Potassium anhydrous sulphite: additive

Definition :

Addition to crushed grapes or to must of gaseous sulphur dioxide, aqueous sulphur dioxide solution, or potassium disulphite[1], ammonium sulphite or ammonium disulphite.

Objectives :

a)        Put into action:

• An antiseptic against problems due to the growth of microorganisms,
• An antioxidant,
• A selective factor for yeasts,
• A product facilitating settling,
• A product favouring the extraction of anthocyanins.

b)       To regulate and control the fermentation.

c)        To produce preserved musts.

Prescriptions :

a)        Sulphiting should take place during crushing or immediately after.

b)       Distribute the product evenly in the crushed grapes or the must.

c)        Ammonium sulphite and disulphite also introduce in the must ammonium ions that constitute growth activators for yeasts (see Activation of alcoholic fermentation).

d)       Products used shall comply with the prescriptions of the International Oenological Codex.

Recommendation of OIV:

Admitted

[1] Potassium disulphite is synonymous with potassium metabisulphite