Sulphur is indispensable in modern winemaking, but it is necessary to know how, when, why and to what extent it should be used. In wine production, sulphur dioxide has multiple roles: it prevents oxidation (browning) of must and wine, acts as an antiseptic (removes unwanted microflora from wine), accelerates clarification of must and wine by precipitation of various impurities that affect quality. Yeasts naturally produce small amounts of sulphur dioxide during fermentation, so each wine contains it in smaller concentrations. The practice of adding sulphur dioxide during the production process to stabilize or preserve wine goes back into the past. A smaller part of the added sulphur dioxide remains free in the wine, i.e. active, and a larger part is bound to certain components of the must and wine. Sulphur concentrations are usually higher in white and rosé wines, and much higher in sweet than in black or orange wines, which receive natural antioxidant protection from tannins. The production of wines without added sulphur is full of challenges, and they are more susceptible to errors, variations in the bottle and premature aging. The use of sulfur dioxide is legally prescribed in every country, which facilitates the production of wine and allows the wine to reach the market without defects and diseases.