Winemaking and S02
Needless to say, sulphur is an indispensable element, not to say essential to life on earth. Whether in the vineyard or the cellar, sulphur has been used since the Romans, who were already aware of its virtues. In wine, sulphur dioxide (SO2) can be used during vinification to eliminate micro-organisms that are not involved in fermentation, but also during bottling to improve preservation. Sulphites are formed when a quantity of sulphur dioxide is brought into contact with the wine. The quality and origin of the sulphur is important; it can be volcanic, the yellow powder, or derived from the petrochemical industry.
Since the last century, industrial processes have become more widespread, and chemistry is increasingly present in food processing. Sulphites have antioxidant and antibacterial properties, which is why they are used as preservatives and are present in many food products. The compounds in the E220 range (from E220 to E228) all belong to the sulphite family. All wines bottled after 8 December 2023 must include a list of the ingredients used and a nutritional table on the label, or a QRCode linking to a web page containing this information.
In the 1960s, a number of enlightened French winemakers set out to make wines without any additives, starting with the most difficult to eliminate, sulphur. The best known of these are certainly Jules Chauvet in the Beaujolais and Pierre Auvernoi in the Jura - the list is too long to mention them all. A community in search of healthy, lively, pure wines.
All wines contain sulphites, either naturally in minute quantities of less than 10 mg per litre, or added in quantities defined for each category of wine: industrial, ecological or natural. Conventional wines contain between 150 and 200 mg per litre, and up to 400 mg for sweet wines. Ecological certification authorises between 100 and 150 milligrams per litre and between 70 and 80 mg for a certified Demeter wine from biodynamic agriculture. A wine is considered natural if it contains less than 20 mg of sulphites per litre. Note the orders of magnitude! The French association Vin Méthode Nature has two certifications, one for wines with no added sulphites and another for wines with less than 30 mg per litre. That said, you can find wines on the market with ecological certification that contain no added sulphites. There are also wines with laboratory analyses of 0 mg. These are known as double zero wines: nothing in the vineyard, nothing in the winemaking process. Easier said than done.