What are Sulfites in Wine? Understanding Preservatives in Wine

What are Sulfites in Wine?

Definition of Wine with Sulfites

Sulfites in wine are compounds containing sulfur dioxide (SO₂) that occur both naturally during fermentation and as additives introduced by winemakers. These chemical compounds serve as preservatives and antioxidants, helping to maintain wine's freshness, color, and flavor profile while preventing premature spoilage. In their natural state, sulfites are produced in small quantities by yeast during fermentation, but most wines contain additional sulfites added at various stages of production.

In the wine-making process, wine is subject to a major risk: oxidation. Due to bacteria incorporated into the wine during the maceration process, the addition of sulfites, particularly sulfur, is necessary to kill these unwanted yeasts and bacteria. These additions help inhibit harmful microorganisms, control oxidation, and stabilize the wine, ensuring wines have their quality preserved.

While sulfites have been used in winemaking for centuries—dating back to ancient Roman times when sulfur candles were burned inside wine vessels—they've become somewhat controversial in recent years due to health concerns among sensitive individuals. Despite these concerns, sulfites remain essential components in most commercial wines, with regulations requiring labeling when levels exceed certain thresholds. It remains mandatory to mention the quantity of sulfites on bottles when it exceeds 10 milligrams per liter.

What is a Wine Without Sulfites?

Definition of wine without sulfites

It's important to know that wines without sulfites don't exist because sulfites are truly essential to the winemaking process. By "wine without sulfites," we're therefore talking about wines that aim to reduce the quantity of added sulfites because these are bad for health if consumed in excess. These are thus wines without sulfites added during production. Among these wines, we distinguish three categories: organic wines, biodynamic wines, and natural wines.

Why drink wine without sulfites?

Wine without sulfites and health

Today, sulfites are present in very many foods. Indeed, while they exist naturally in certain foods, there are a very large number of added sulfites among other additives to extend the shelf life of foods or to fight against bacteria. Sulfites are found under these names: potassium bisulfite, potassium metabisulfite, sodium bisulfite, sodium dithionite, sodium metabisulfite, sodium sulfite, sulfur dioxide, sulfuric acid, sulphites, sulfites, and sulfiting agents. However, sulfites consumed in too large quantities endanger health. Sensitivity to sulfites causes a form of food allergy. Consuming wine without added sulfites therefore reduces health risks and more broadly falls within a reasoned consumption approach.

Wine without sulfites and environment

White wines without sulfites and red wines without sulfites do not directly preserve the environment. Nevertheless, most wines that are without added sulfites are organic, biodynamic, or natural wines and therefore part of a responsible approach. This responsible approach not only reduces the use of sulfites but also tends to prohibit the use of chemical plant protection products and pesticides. Indeed, these chemical products are so powerful that in the short term they also eliminate harmless fauna and flora as well as pests. In the long term, the land is deeply damaged and the balance of ecosystems is completely disrupted. Wines without sulfites are therefore generally a more sustainable solution than traditional wines.

Wines without sulfites: Organic wine

What is an organic wine?

Organic wine aims to offer good wine that is both healthy and responsible. Since 2012, the name "organic wine" has been protected and regulated by the European Union both in terms of viticulture and winemaking. The objective of organic white wines and organic red wines is to prevent the use of pesticides, insecticides, and chemical treatments. This approach is part of a global trend and consumers' desire to consume less but better. Indeed, we observe a progression of the organic wine market year after year.

Do organic wines contain sulfites?

The answer is yes. Indeed, it is very complicated for a wine to completely do without sulfites, especially for a white wine. While red wine naturally presents tannins and antioxidants, white wines, whether dry or sweet, have little chance of aging correctly and maintaining themselves without the addition of sulfites. Nevertheless, organic wines greatly reduce the addition of sulfites: we observe much lower doses that guarantee fewer harmful effects on health.

Wine without sulfites: Biodynamic wine

What is a biodynamic wine?

If by "organic wine" we tend to think of "organic wine" and "biodynamic wine," we should not confuse these two denominations. Indeed, biodynamic wine responds to an extremely precise specification that aims to balance the forces of the earth. To do this, treatments in the vineyard are made from plants and infusions to offer more robustness to the earth, and work in the vineyard is implemented according to the lunar calendar so that plants naturally have better resistance. In general, biodynamic wines come from a philosophy that thinks of nature as a set of living ecosystems that must be listened to, respected, and protected.

Do biodynamic wines contain sulfites?

The answer is yes. Nevertheless, since the earth, the cycles of the moon and sun, and the life of ecosystems are paramount for biodynamics, the wines that come from it are part of the most natural approach possible. Very similar to organic wines, biodynamic wines are also wines without sulfites insofar as they contain very few. The flagship labels of biodynamics like the Demeter label and the Biodyvin label have a very strict set of specifications that imposes sulfite quantities even lower than those authorized by the specifications of organic viticulture.

Wine without sulfites: Natural wine

What is a natural wine?

By natural wine, we also mean nature wines. They have existed for centuries, but it's the appearance of a natural method wine label that has recently given them structure and more credibility and visibility. Natural white and red wine brings together unfiltered wines that show an aromatic profile with qualities as well as defects. The cultivation of the vine is similar to those used by organic and biodynamic viticulture, that is, with the greatest respect for nature, without chemical treatments and rather with natural fertilizers. Harvesting is always done manually.

Do natural wines contain sulfites?

The answer is yes. But natural wines are the big winners of wines without added sulfites: they contain even less than their counterparts, organic wine and biodynamic wine. The rate of sulfites present in natural wines is close to zero, and some domains don't add any at all. The yeasts used instead are indigenous yeasts, that is, natural yeasts. The result is extremely authentic since here it's nature that has the final say. They offer a unique experience, and it is very difficult to establish a typical aromatic profile of natural wines.