Sulphites in natural and organic wine
What is the purpose of sulphites in wine?
It's a natural companion to wine. Sulphites or sulphur (or SO2) have 4 main properties:
- preservative: they protect the wine from oxidation by combining with oxygen.
- antiseptic and antifungal: they help control alcoholic fermentation by blocking the development of bacteria and certain yeasts. They kill fungi and moulds and finally disinfect barrels and equipment.
- stabilising and controlling: they help to promote the yeasts that are more efficient for alcoholic fermentation by blocking certain other yeasts.
- dissolving and clarifying: they accelerate the decomposition of the grape and the release of tannins and aromas. They precipitate certain components such as polyphenols.
It is therefore very useful and very tempting to add more than reason to the many stages of the winemaking process. When disinfecting barrels: this is done by burning a sulphur wick. The burning of the sulphur then gives off so2 sulphur dioxide and an odour of rotten eggs. This sulphur dioxide penetrates the wood of the barrel and then migrates into the wine. When the barrel is filled, in the presence of the water contained in the wine, it will be transformed into sulphurous acid. During the grape harvest: when the grapes are broken up by the different manipulations, the sugar comes into contact with the oxygen in the air. Sulphites are used in order to avoid the start of uncontrolled alcoholic fermentation.
- During the alcoholic fermentation: if it goes beyond the desired criteria.
- In the special case of mutage. This step stops the fermentation of the slack and preserves the residual sugars in order to obtain these so-called sweet or syrupy wines.
- At the end of the alcoholic fermentation: to block the malolactic fermentation.
- During air racking: when the wine is transferred from barrel to barrel during its maturation.
- Just before bottling: in order to stabilize the wine for transport and marketing.
What is a wine with no added sulphites or wine with no added sulphur?
It is a wine that during its development from the vine to the bottle has not seen the addition of sulfur. That is to say without added sulphur or sulphite. On the other hand, sulphites are formed in the wine during fermentation. Indeed, the development of yeasts is accompanied by the formation of sulphur compounds that will be found in the wine: of course in very low dosages. It is therefore very rare to have a wine whose analysis shows a nil result.
Why do some natural winemakers add sulphites?
Yeasts during fermentation can produce between 5 and 30 mg of sulphur. Of course, if the grapes produced are worked organically or biodynamically, they contain much less sulphur compounds. The natural sulphur content of the wine produced is then much closer to 5mg/l than 30mg/l.
The winemaker "nature" wine shop relies heavily on these "natural" sulphites to stabilise its wine and make it a success. But to achieve this requires very precise working methods, which are more expensive and require lower yields in the vineyard. But it is above all a great experience in winemaking without added sulphite that is most important. Expertise that requires time, mastery, trials, etc...
Also, rather than lose everything, winemakers add sulphur to their wine. Most often, it is during bottling to stabilize and secure their production. They will nevertheless do so by seeking the lowest dose.
Why can I have the words "contains sulphites" on a bottle of natural wine?
The European Union requires the label (or back label) to state: contains sulphites, contains sulphites. There are also two other inscriptions that are very rarely used: contains sulphur dioxide or contains sulphur dioxide. This indication may or may not be accompanied by the code of the family of European preservatives, the famous e220.
Since 2005, the European directive has applied to all wines with a sulphur content of more than 10 mg/l. In the United States, from only 1 mg/l. However, these regulations do not yet oblige producers to mention the amount of so2 present in their wine.
Most of the time, winemaker will still indicate "contains sulphites" to protect themselves from the legislation. Even if his wine has not had any sulphite added.
Why do sulphites make your head hurt?
After drinking one or more glasses of wine, the headache felt is not due to alcohol. It is due to the (unnatural) sulphites it contains. In conventional winemaking, sulphites are added to the wine for its good conservation and to prevent the fermentation from spoiling it. Sulphites can be unpleasant for humans, however. Among other things, they can cause nausea and headaches.
In general, sweet wines contain the most sulphur and red wines the least. "White wine tends to cause more headaches than red wine," we often hear. To some extent, that's true. Whites and reds contain different concentrations of the two families of substances implicated in headaches. Sulphites, sulphur compounds used as colour stabilisers, and biogenic amines (histamine, ethylamine...), produced during grape fermentation. They are often added to white wines to prevent them from turning brown. Red wines need less of them because they benefit from the antioxidant protection of naturally occurring polyphenols. As for biogenic, allergenic amines, their concentration is not linked to the colour of the wine. It can change according to the variety of Grape variety (chardonnay, pinot, merlot...). Sulphur has a vasodilating effect on blood vessels, causing pressure in the brain and consequent pain. Of course, the simultaneous presence of a high level of amines and sulphites is the most favourable case for triggering headaches.
Since 2005, legislation has obliged wine manufacturers to mention the level of sulphites on their bottles.
Is there an alternative to sulphites?
Natural wine is the result of a philosophical choice aimed at recovering the natural expression of the terroir. It is made from organically grown grapes, without weed killers, pesticides, fertilizers or other synthetic products. The harvest is manual and during the winemaking process winemaker strives to keep the wine's lively character. Technical interventions that could alter the bacterial life of the wine are prohibited. This is also the case for the addition of chemical products, with the exception, if necessary, of sulphites in very small quantities. The maximum doses of total SO² tolerated are 30mg/l for reds and 40mg/l for whites. Antioxidant, antiseptic, anti oxidasic, solvent, sulphur (or sulphite) is a broad-spectrum preservative. It is, moreover, easy to use and inexpensive. Problem: it gives a headache (see previous lines) and masks the natural aromas of the wine when used in excessive doses. And it is ultimately, when it is chemically manufactured, a toxic product.
How can we avoid this addition of sulphites, or at least try to use as little as possible?
It is a global approach which is chosen by winemaker. The objective is, for each stage of the process, to have the least contact with oxygen and/or the maximum avoidance of contaminating micro-organisms. To put it simply, everything at winemaker wishing to work without sulphur must be impeccably clean. At each stage - from viticulture to winemaking - winemaker will be able to avoid adding as much SO2 as possible.
In a certain number of cases, it is undoubtedly possible to make wine without sulphur because there is always some naturally present in the lees. This does not apply to late harvest wines or sweet wines.
If the wine is shipped with good temperature control. And if it is stored in good conditions and does not travel too far, it can be done. But unfortunately accidents are still frequent.
The question that is almost never asked is: what sulphur are we talking about?
Natural wine is the result of a philosophical choice aimed at recovering the natural expression of the terroir. It is made from organically grown grapes, without weed killers, pesticides, fertilizers or other synthetic products. The harvest is manual and during the winemaking process winemaker strives to keep the wine's lively character. Technical interventions that could alter the bacterial life of the wine are prohibited. This is also the case for the addition of chemical products, with the exception, if necessary, of sulphites in very small quantities. The maximum doses of total SO² tolerated are 30mg/l for reds and 40mg/l for whites. Antioxidant, antiseptic, anti oxidasic, solvent, sulphur (or sulphite) is a broad-spectrum preservative. It is, moreover, easy to use and inexpensive. Problem: it gives a headache (see previous lines) and masks the natural aromas of the wine when used in excessive doses. And it is ultimately, when it is chemically manufactured, a toxic product.
In conclusion:
It is a global approach which is chosen by winemaker. The objective is, for each stage of the process, to have the least contact with oxygen and/or the maximum avoidance of contaminating micro-organisms. To put it simply, everything at winemaker wishing to work without sulphur must be impeccably clean. At each stage - from viticulture to winemaking - winemaker will be able to avoid adding as much SO2 as possible.
In a certain number of cases, it is undoubtedly possible to make wine without sulphur because there is always some naturally present in the lees. This does not apply to late harvest wines or sweet wines.
If the wine is shipped with good temperature control. And if it is stored in good conditions and does not travel too far, it can be done. But unfortunately accidents are still frequent.
