Why are there sulfites in wine, are they dangerous ?

Jean-Michel Quinoa, I know ... you are allergic to gluten, lactose and sulphites.

Technically, this additive is used for its antiseptic properties, antioxidants and antioxydasics. In other words, sulfites prevent "bad microorganisms" from making wine vinegar, while letting the "nice micro-organisms" do their job : turn grapes into wine.

It should be understood that SO2 is an essential input in wine, since currently no oenological additive can replace it.

What are the regulations for the use of sulphites ?

Authorized up to doses of 450mg / l in 1926, the use of the sulphur is much more controlled and the current thresholds are :

• Between 150 to 200 mg / l for reds,

• Between 200 to 250 mg / l for whites and rosés, 300 mg / l for the whites of certain AOCs and 400 mg / l for sweet white wines such as Sauternes, Coteaux-du-Layon, and so on.

• Between 185 at 235mg / l for sparkling wines.

For wines from organic farming, the maximum authorized levels are :

A wine processed without adding sulfur during vinification is said to be "without added sulfur" but you will still see the legal notice "contains sulphites", mandatory as soon as the SO2 content is greater than 10 mg / l, because yeasts naturally produce SO2 in wine at a level of around 30mg / l. These so-called "no added sulfur" wines present the risk of contracting the wine diseases against which man has sought to fight for centuries !

How long have they been used in wine ?

During the Roman Empire, viticulture has undergone considerable development. The daily consumption of wine increases and leads to an increasing demand for this precious nectar, the peak of which was estimated at the end of 10 to 20 minimum age. Transport and prolonged aging raise the question of their conservation very early on.

For Pliny the Elder, wines that can be stored without adding anything to the must are the best, which is almost impossible when you know the propensity of grape must to want to turn into vinegar ... Man has tried everything to prevent wine from becoming sour : we added raw resin, we also tried the pitch (baked resin), or must reduced by boiling as well as aromatics, sometimes even seawater ... But none of these methods were miraculous.

The use of sulfur is not recent. In his treatise De Re Rustica, Caton (between 243 before. B.C.. to 149 before. Christ) explains the need to take care of the casks and recommends closing the slits with lut, a coating that consists of a pound of wax, a pound of resin, and half the sulfur. He also mentions a "way to save the vine from the ravages of the naughty worm, by spraying a mixture containing, among others, "A third of bitumen, and a quarter of sulfur ". On the other hand, certainly misunderstanding the principles of fermentation, sulfur was not yet used during winemaking.

It was not until the 18th century that we really observe the factors of degeneration of wine and the positive use of sulfur. Nicolas bidet, sommelier of Queen Marie-Antoinette, explains in his "Treatise on Nature and the Culture of the Vine, on wine, how to do it and how to govern well. For the use of the various vineyards of the Kingdom of France "of 1752, that "the fresh air corrupts and diminishes the quality of the wine" and that the wines "put in the cellar acquire a much higher quality than they had before". He explains that "the custom of running a little bit of wick in the barrel" during the first clearing (wine clarification / filtration stage) prevents the wine from getting stale.

In 1807, Jean-Louis Chaptal observes that the sugar content of the must influences the quality of the wine. The sweeter the grape is, the better the fermentation proceeds, and the wine keeps better over time. In the event of a bad year, he recommends in his book "The art of making wine" to add sugar to the must, explaining that "the addition of sugar has the double advantage of significantly increasing the alcool of the wine, and to prevent the acid degeneration to which weak wines are subject ”. He also describes the moulding technique practiced at that time : "We put the must in barrels that we fill to a quarter ; we burn several wicks on it, we put the cap on, and the barrel is shaken vigorously until no more gas escapes from the bung when it is opened ". This heavily sulphurous must is called "silent wine", because unable to ferment, is then added to the final wine at the rate of two or three bottles per barrel.

Winemaking methods make a real leap forward thanks to Pasteur with the entry of science into the world of oenology. Seeing that the diseases of wine were bad for his business, Napoleon III asked Louis Pasteur to find a "remedy". This is how the precise mechanisms of wine fermentation were discovered. Originally from Jura, Pasteur observed wines aged under veil. There he discovered that the latter was made up of "very pure mycoderma vini", but on the contrary, "And without any exception, the flora was a mixture of mycoderma vini and mycoderma aceti when the wine turned acidic ”. Pasteur had just identified a microorganism known as the "acetic bacteria" responsible for the transformation of wine into vinegar.

In parallel, Pasteur also studies shoot disease. The latter is characterized by the accidental presence of carbon dioxide in a wine which must not contain any.. The wine is cloudy, becomes slightly pearly and bland. He discovers the presence of a ferment very different from the alcoholic yeast in wine. This forgotten disease is caused by the presence of lactic acid bacteria which break down tartaric acid, producing acetic acid and gas. They are also responsible for other problems : increased viscosity of wine, bitterness.

Pasteur therefore concludes that "wine diseases are correlative of the multiplication of parasitic vegetations, and that in the absence of these cryptogams the wine ages without alteration ". To avoid the sulfurization processes known at the time, Pasteur suggests heating the wine to a temperature of over 50 ° C : the concept of pasteurization was born. However, this method was too brutal for the wine and therefore not very interesting.

It’s much later, that we could use SO2 as a liquid gas, aqueous solution, or effervescent tablets. This now allows for more precise dosing and control.

Are sulfites dangerous for health ?

Now that you know almost everything about sulfite, I feel this question burns your lips : should i beware of sulphites in wine ? Am I allergic and will my arms fall as I read on doctissimo ? Is Jean-Michel Quinoa right in telling me that I am going to die because of the sulphites in the wine ?

Today, sulphites are used in different products and yet I have the impression that wine is the only product to really suffer... It should not be forgotten that they are also used as preservatives in dried fruits and meats.

In fact, transforming grapes into wine naturally produces sulfur dioxide, but it is necessary to add more to reach an optimal concentration. A few cases of sulfite intolerance have been observed in asthmatics. As a reminder, sulfites serve as preservatives. They serve as oxygen trap : instead of oxidizing the wine, the oxygen will oxidize the sulphite. Like sulfur is an oxygen trap, people who are immunocompromised or have difficulty breathing will have a little more trouble breathing than others, causing headaches, redness, sneezing, and so on.

It is estimated that between 3 to 10 % asthmatics may have reactions related to the presence of sulfites. This means that less than 1 % of the population can honestly say they are intolerant to sulphites. To compare, you are just as likely to be schizophrenic or epileptic...

To see if your friend Jean-Michel Quinoa is really intolerant to sulfites, just give him a handful of dried fruit and wait to see if he rolls on the floor. As our modern wines oscillate between 20 to 200 PPM, the handful of dried fruits that you have just handed him contain between 500 to 3 000 PPM ! Industrial dishes are also sulphite nests since it suffices to note that many of them contain one of the preservatives ranging from E220 to E228 - which is equivalent to sulphites –.

Often, we wrongly accuse sulphites, but the most probable hypothesis points to other culprits. We think especially of the histamine present in the skin of the grape. This natural substance, which is a derivative of ammonia, has the annoying tendency to dilate the blood vessels.