Sulphites or sulfur dioxide (SO2) is a natural by-product that occurs in wine during fermentation stage. Hence all wine will contain a trace or a low amount of naturally occurring sulphites.
The difference comes is the amount of ‘added sulphites’.
Natural or ‘no added sulphites’ wines are wines that are made with either no sulphites added during wine making process or a very low quantity added.
Why are sulphites added to wines?
Sulphites are very important for the wine. They protect the wine from any bacteria during wine making process, from oxidation once the bottle is opened, from temperature changes and movement during transportation process.