Sulfites in Wine Explained

As you pop the cork on that nice bottle of claret, you may notice the words “contains sulfites” on the label, and they may give you pause. It is an intimidating word. Is this a red flag? Or are wine sulfites beneficial?

Sulfites and Wine: What is the Relationship

Sulfites occur as a by-product in the winemaking process naturally, but are also added artificially to stop fermentation and preserve the wine.  Under the limits set by government food regulatory agencies, there has not be any proven general medical danger. A lot of people drink a lot of wine and don’t seem to develop a medical condition related to sulfites. But some individuals with allergies, asthma, enzyme deficiencies and other health conditions should consult your doctor and proceed with caution.

Wine grapes

Natural Origin

The term “sulfites” means sulfur dioxide, which is a preservative used mainly in dried fruits, soft drinks, and alcoholic beverages. It has antioxidant and antimicrobial properties and naturally occurs in the fermentation process. Wine sulfites are in both molecular and gaseous states. The molecular sulfur dioxide binds with other molecules, and this keeps bacteria from growing, keeps the wine fresh, and prevents it from turning to vinegar. The gaseous sulfur dioxide exists in free form, and may make the wine taste odd if there is too much of it.

There are limits on how much sulfur dioxide can be added to wine. In the United States, wine sulfites can’t exceed 350 parts per million. European red wines can have up to 160 ppm, white and rose wines up to 210 ppm, and sweet wines up to 400 ppm. In both places, if a wine has 10 ppm or fewer, the label doesn’t have to read “contains sulfites.”

At Risk Groups

Please consult with your doctor if you have any condition that is related to sulfite reactions or belief that exposure to sulfites harms your health. Avoiding wine may not be enough to cut out all exposure to sulfites.

Why do people object to wine sulfites? One of the biggest complaints is that wine sulfites cause headaches. Many people believe that red wines contain the most sulfites and cause the most headaches. Actually, wines in the United States all have the same limit on wine sulfites, 350 ppm, and in Europe red wines have the lowest limit at 160 ppm. European sweet wines do have a limit of 400 ppm, and many sweet wines are red. On the other hand, there are other substances in wine that can cause headaches, such as tannins, histamines, and alcohol. It may be hard to pin headaches on the wine sulfites alone.

Red Wine - Mr T in DC
Red Wine – Mr T in DC (Photo credit: USDAgov)

A serious concern with wine sulfites is sulfur dioxide sensitivity. Many people are allergic to sulfur dioxide, and can suffer from hives, seizures, vomiting and asthma, and can even have fatal respiratory failure. This can be caused by drinking the wine or by inhaling the free form gas in the wine. People who are allergic to wine sulfites should definitely avoid drinking wine with sulfur dioxide added.

Why Sulfites Are Necessary, But Not As Necessary As They Used to Be

Winemakers have been adding wine sulfites mainly because wine is perishable. Without them the wine may have a shelf life of only a few months, depending on the conditions it’s stored in. Bacteria also form a constant threat that sulfites counter. Winemakers are concerned about how long the wine will sit around unsold. Adding wine sulfites gives the maker the assurance that the wine won’t spoil before it’s bought.

However, because of public perceptions and allergy dangers, many winemakers are finding ways around adding wine sulfites. For one thing, sulfur dioxide exists naturally in wine due to the fermentation process. Red wines that contain natural wine sulfites and tannins can often stay fresh without added sulfur dioxide. Also, better winery hygiene and healthier grapes are reducing bacteria growth and the need for preservatives. It’s easier now for consumers to find wines made without wine sulfites. In the United States, wines labeled “organic” are made with no added sulfur dioxide.

Wine sulfites, like many additives, offer both risks and benefits that have to be balanced. Ultimately, consumers have to decide for themselves if wine with added wine sulfites is the right buy for them.