Without sulfur dioxide , aka sulfur dioxide , wine becomes acidic. True antiseptic, SO2 protects the wine throughout its development process and even after, once bottled. A magic potion to dose with intelligence!
Originally there was sour wine. The great evolution of Bordeaux in the 18th century and the birth of modern enology constituted an enormous advance in terms of hygiene, and the use of sulfur dioxide revolutionized the quality and conservation of wines .
Sulfur dioxide ( SO2 ) is an antiseptic . Used sparingly (depending on the vintage, the type of wine and the health of the harvest), it protects the wine from oxidation and stabilizes it once bottled. Temperature variations are therefore more easily tolerated.
When is sulfur dioxide added?
Generally sulfur dioxide is added when the grapes are placed in the vats, sometimes even during the harvest. It can be added at the end of alcoholic fermentation to block the malolactic transformation , during ageing, to prevent the development of bacteria , or even during filtration and bottling.
Too much or no sulfur dioxide?
Yeasts naturally produce SO2 : it is therefore false to state that there are wines without sulphur, but wines without added sulfur dioxide. Used without discernment however, sulfur dioxide can also cause discomfort. Its excess can annoy and even cause headaches . Naturally the whites , and in particular the sweet wines , which are more fragile, always contain a little more sulfur dioxide than the reds because their tannins act as natural stabilizers.
The maximum doses authorized by the European Union are 150 mg for a red wine, 200 mg for white and rosé wines and 300 to 400 mg for sweet wines . Note that organic and biodynamic producers use much less.