Sulphites in Wine

The term “sulphites” refers to sulphur dioxide added to wine. Sulphites in wine have primarily antioxidant, preservative and antimicrobial properties. In many respects, they are indispensable for the quality of wine itself. Regardless of the additions made by winemakers, it should be noted that sulphur dioxide is present in wine naturally as well, in very small quantities. Fermentation triggered by yeasts present on the grape skins indeed produces sulphites.

Sulphur dioxide may be present in foodstuffs – not only in wine – in controlled quantities and below certain legal limits. This is because sulphites are considered allergens and can trigger reactions in particularly sensitive individuals. For this reason, their presence must always be indicated on the label. It is permitted to use the term “contains no added sulphites” only if the concentration is below 10 mg/litre.

Sulphites are a common category of chemical substances frequently used in food industry processing. Particularly for their preservative power: thanks to their antimicrobial and antioxidant capabilities, sulphites preserve foodstuffs and protect them from the proliferation of harmful bacteria.

In wine, they are added at various stages of production and in various forms (often as a solid, added as a salt). Generally, they serve to control the wine’s evolution, prevent defects from occurring and direct the fermentation and maturation process in the desired direction.

The addition of sulphites to wine must be made within legal limits. In Europe, the limits are set at 160 mg/litre for red wines, 210 mg/litre for white and rosé wines and 400 mg/litre for sweet wines. In organic wines, the threshold is lower at 100 mg/litre for reds and 150 mg/litre for whites.

In the wines of Cantine Leonardo da Vinci, sulphites are added at each stage of winemaking for preservative and antimicrobial/antibacterial purposes, to ensure a healthy and quality wine.