What Are Sulfites in Wine (And Why Do They Matter)?

From talk about their necessity as a preservative to gossip around their ability to cause a “wine headache,” sulftes in wine are often a hot topic and the topic of debate.

And yet, sulfites are naturally present in wine and can provide several advantages when intentionally added by winemakers.

So, what are sulfites, why are they in wine and should you be nervous about them?

Here’s what you need to know.

What Are Sulfites And Why Are They Added to Wine ?

Sulfur dioxide (SO2)—commonly known as sulfites—is a group of chemical compounds found in many foods and drinks, including wine.

Just one of the thousands of chemical byproducts of fermentation, sulfites develop naturally, at low levels, in every wine.

However, because it acts as an antioxidant and an antiseptic, SO2 is also often added and adjusted during several parts of the winemaking process to preserve a wine’s flavor, color and overall character, and to extend shelf life by helping to block the growth of bacteria.

Sulfites can also be used to stop fermentation, which allows winemakers to control the amount of residual sugar left in the final wine, and certain types of SO2 can be used to sanitize winemaking equipment and aging vessels.

Levels Of Sulfites in Wine

Sulfite levels vary from wine to wine.

Naturally occurring sulfites developed during fermentation are uncontrolled and differ from wine to wine. And though there are strict regulations around sulfite additions made by the winemaker, there’s not a single standardized level used for all wines.

Generally speaking, sweet wines often have higher SO2 levels than dry wines. This is because additional sulfites may by added to avoid unwanted fermentation of their residual sugars and prevent spoilage during storage.

Dry red wine typically has the lowest levels of sulfites, thanks to prolonged contact with antioxidant-rich grape skins during fermentation that offer increased natural protection from oxidation, discoloration and spoilage. Wines with higher acidity, which are naturally more resistant to bacteria, also typically require fewer added sulfites.

Winemakers may also choose not to add any SO2 or to add just enough to ensure the wine remains stable, and nothing more. These may be, but are not required to be, labelled as “low sulfite” or “no added sulfite” wines.

In the US, the Alcohol and Tobacco Tax and Trade Bureau (TTB)—an organization that collects taxes and enforces regulations on alcohol, tobacco, firearms and ammunition—requires that wines containing 10 parts per million (ppm) or more of sulfites must include the statement “Contains Sulfites” on the label.

Can You Taste Sulfites in Wine?

Typically, sulfites are not tasted in wine. Their use is tightly regulated and they are used in such tiny amounts that they don’t significantly impact the wine’s flavor. In very rare occurrences, a winemaker’s overuse of SO2 can produce a smell similar to a burnt matchstick.

Are Sulfites in Wine Bad?

For most, the sulfites in wine pose no health risks. In fact, there are often more sulfites in dried fruit than there are in a glass of wine.

According to the Food and Drug Administration (FDA), an estimated 1% of the US population is sensitive to sulfites, and the most common reaction experienced by these individuals is a sinus irritation—not the headache with which they are often associated. (Other adverse effects include flushing, fast heartbeat, wheezing, hives, dizziness, stomach upset and diarrhoea, and in the case of severe allergic reaction, difficulty swallowing and anaphylaxis.)

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What Are Sulfites in Wine (And Why Do They Matter)?

What Are Sulfites And Why Are They Added to Wine ?

Levels Of Sulfites in Wine

Can You Taste Sulfites in Wine?

Are Sulfites in Wine Bad?

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