Why does wine contain sulphites ?

Why does wine contain sulphites ?

There are many misconceptions about sulphites in wine. However, they are naturally present in wine, and are essential for its good behaviour and preservation. So why are sulphites the subject of debate? Why does wine contain them? A brief overview of the importance of sulphites in wine.



The wine making inevitably goes through a stage of alcoholic fermentation. This process, under the action of yeasts, will transform the sugar in the grapes into alcohol, but also produce what is commonly called sulphur. It is a natural chemical reaction inescapable. Thus, the presence of sulphites in wine A chemical compound of the sulphur family, is the result of a natural process, even if it is present in very small quantities.

Although we usually speak of sulphites or sulphur, it is also possible to refer to this compound by other terms, such as sulphur dioxide (SO2), sodium sulphite, sodium bisulphite, or sulphiting agents.



We have just seen that the wine naturally contains sulphites even in very small quantities. So what is a "sulphite-free" wine? We are talking about a wine that has not had sulphites added to it.

To find a wine without added sulphites. It is then advisable to turn to a natural wine which comes from a particular wine production. In the first instance, no plant protection products are used on the vines. In this way, sulphur is not present in the harvested grapes. Secondly, no products are added to the wine-making process. The sulphites present in natural wines come solely from the natural process of alcoholic fermentation.

natural wine contains an average of 30 mg per litre of sulphites, compared to 100 to 200 mg per litre for other wines, whether red, white or rosé. The level can even rise to 400 mg/L for sweet white wines. France has imposed legal limits of sulphur content of wine. This also varies according to the sugar content of the wine. The maximum limits for sulphites in wine are thus between 150 and 250 mg/L (400 mg/L for special wines). In addition, the mention " contains sulphites "The label of the wine must be marked with the word 'sulphite' if the level of sulphite exceeds 10 mg per litre.



The addition of sulphites to wine is designed to counteract the harmful effects of oxygen on wine. Indeed, naturally present in wine, oxygen in the air progressively transforms it into "vinegar", making it unfit for consumption. Sulphites have two very interesting properties to fight against this phenomenon:

  • Antioxidant by limiting the process of wine oxidation Sulphur brings more resistance to the wine;
  • Antiseptic Sulphites also fight against yeasts and bacteria present in the wine, and thus help to maintain a balance in the microbial flora of the wine, favouring better conservation.

The sulphites in wine therefore act as a protection against all possible alterations to the wine.



If sulphites are so much debated, it is mainly because of the reactions they can produce in humans after consumption. Indeed, although sulphites are harmless to health, it is not uncommon to develop a sulphite allergy. It is then possible to have a runny nose, hives, or abdominal pain. The consumption of sulphites is therefore prohibited.

But the most common rumour about sulphites is their propensity to give you a headache. However, there is no scientific evidence that sulphites cause headaches. It must be recognised that it is rather the excessive consumption of alcohol that causes headaches. However, the wines that contain the most sulphites are also those that contain the most alcohol.


Many producers add sulphites to their wine. The legislation is firm on this use, and there is no evidence to date that sulphites are harmful to health. Legislation is firm on this use, and there is no evidence to date that sulphites can be harmful to health. If in doubt, there are more and more very good wines without added sulphitess, particularly in organic wines.