Sulfites in wine indicates Sulfur Dioxide (SO2) has been added to the wine during production. This has been widely used in winemaking because of the antibacterial and antioxidant properties, which helps the wines to stay fresh over longer periods of time. This can be seen as a great additive for wines which have great ageing potential.

  

Sulfur free wines are thought to be purer or more natural as they have less additives and hold the natural yeasts of the bloom of the grapes. Sulfur dioxide removes the natural yeasts from the bloom of the grape, so the winemakers can alter the yeast and adapt this to how they want this to taste.

   

Consuming sulfites is safe, however a minority of people suffer from consuming this. Symptoms such as breathing difficulties and other allergy like symptoms.

  

The EU regulate the levels of sulfur dioxide that a wine is permitted to contain, which is restricted at a maximum of 210 parts per million (ppm) for white wine, 400 parts per million for dessert wine and 160 parts per million for red wines. Any wine which holds more that 10 parts per million must clearly indicate on the label that it 'contains sulfites'.