🍷 Sulphites (SO2)

Sulphites are salts of sulphurous acid, and in winemaking the term usually means sulphur dioxide, SO2, and the additives that provide it. They protect wine from spoilage and oxidation. Without them wine loses flavour and colour faster.

A little sulphite forms by itself during fermentation. In addition, the winemaker adds it, for example as potassium metabisulphite. An old method is sulphur fumigation: sulphur is burned in a barrel to kill harmful microbes. Sulphite limits are set by law and by the international code of oenological practices.

For most people sulphites in wine are safe. But in some, especially people with asthma, they can cause a reaction, which is why labels say contains sulphites. This is called sulphite sensitivity.

Sulphites occur not only in wine but also in dried fruit and other foods. If in doubt, ask a doctor.