Sulphites in Wine, What Are They?

Every couple of years, the debate about sulphites in wine resurfaces. It is a common topic amongst winemakers and wine enthusiasts, and one worth exploring for sulphites' effect on wine quality and potential health effects. Sulphites are often misunderstood and characterised as harmful wine additives, but is this reputation justified?

This guide will explore sulphites in wine in-depth and explain their origins, composition, and uses. Low-sulphite and sulphite-free wines are in vogue, and they are changing the market’s perception towards even the most classic wine regions; therefore, understanding sulphites is necessary to make adequate purchase decisions. Let’s discuss the use of sulphites in the wine industry and their importance.

What are Sulphites?

Sulphites or sulfites are chemical compounds that occur in nature; they are present in our food and ourselves. They are also additives used in a wide range of industries for their ability to protect organic matter from oxidation and antiseptic properties. Sulphur dioxide, or SO2, is the most common sulphite, especially in winemaking, but there are others.

The Ancient Romans already used sulphites in the form of sulfuric candles, which they would burn to sanitise clay amphorae that would hold wine. The practice continues, in one way or another, to this day. However, sulphites are used not only in wine production but also in the food industry. Most processed, canned and frozen foods are sprayed with SO2 to extend their shelf lives.

Sulphites in Wine

Sulphites protect wine from oxidation and, in the process, stabilise or ‘fix’ its colour while preventing spoilage. SO2 is not only a potent antioxidant but an antiseptic, and will prevent wine from being transformed by rogue yeast or bacteria.

Winemakers use sulphites during several steps of the winemaking process. They might spray SO2 on crushed grapes to prevent them from growing wild yeast or harmful bacteria and add it to fermented wine to prevent further evolution. Even a tiny sulphite dose before bottling is customary to ensure the wine arrives at its destination undisturbed by unwanted microorganisms.

Not using sulphites during winemaking doesn’t ensure the wine is free from the compound, as it occurs naturally during fermentation. Nonetheless, insufficient sulphites might cause wine to re-ferment or oxidise prematurely, so winemakers use it judiciously within the quantities their government allows.

If the sulphite concentration in wine is greater than 10 ppm, winemakers must include “contains sulphites” on the label, which has caused consumers to question the compound’s safety. However, the statement is meant to protect people sensitive to the compound. Generally, wine contains around 125 ppm, within the safe limit for most of the population.

Tasting Sulphite Free Wine

When producers make wine without sulphites, they do so to preserve the wine’s natural organoleptic properties — its colour, flavour and aroma. Not using or limiting sulphites is a statement against highly processed and manipulated wine, and it is to be applauded. Nevertheless, when wine is not protected from oxidation, it behaves differently; it is prone to oxidation, bacterial contamination and spoilage. So-called ‘natural’ wine, made with no additives, has shorter ageing potential and will evolve faster than wine protected by sulphites.

Although noteworthy wineries and prestigious winemakers promote the idea of non-interventionist winemaking, they limit sulphite use but don’t omit it. Natural winemakers might have a point, as additive-free products are almost always a better alternative. Still, they are not excused from making faulty wine under the excuse of making natural wine. Unless subtle and controlled, oxidation in wine is rarely a trait but a fault, and many sulphite-free wines show faults shortly after being bottled.

What does sulphite-free wine taste like? When done right and within a reasonable period after bottling, sulphite-free wine should taste as good as regular wine without noticeable differences. Once the wine loses its battle against oxygen, its colour will change from straw to golden and red to tawny. Sherry-like aromas will also become present in oxidized wine, and the chance of picking up scents from wild yeast and bacterial contamination will increase.

Frequently Asked Questions

Are sulphites safe?

Yes. In most cases, sulphites are safe. Sulphites are used widely in the food and beverage industry, and their use is regulated in most countries. The use of sulphites requires regulation because between three to ten percent of people with asthma are sensitive to the compound and can experience allergic symptoms. Non-asthmatic people can be sensitive to them, too. Nevertheless, contrary to common belief, wine is not amongst the foods and beverages with the most sulphites; dried fruit and processed food, like frozen fries, contain ten times more sulphites than wine. Consult a medical professional if you suspect being allergic to sulphites.

Do sulphites cause headaches?

No, sulphites don’t cause headaches. A common myth about sulphites is that they cause headaches and hangovers. While it is true that some people are sensitive to the compound, most people aren’t. This doesn’t stop many people from blaming sulphites for the aftereffects of drinking wine. What causes headaches and hangovers is alcohol, or, more accurately, the dehydration caused by consuming it in excess.

What is the difference between sulphates and sulphites?

Both sulphates and sulphites are natural chemical compounds made of molecules that combine sulphur and oxygen atoms. Sulphates comprise one sulphur and four oxygen atoms and have no antioxidant properties; they are, instead, used in detergents and other household and industrial products. On the other hand, sulphites contain fewer oxygen atoms and have antioxidant properties; these are used to preserve food and beverages, and the most common is sulphur dioxide or SO2, not properly a sulphite but a closely related chemical oxide.

Is sulphite-free wine better than regular wine?

Sulphites naturally occur in fermented products, so no wine is genuinely free of the compound. Of course, products with fewer additives are often a better alternative to those manipulated extensively. People often consider sulphite-free wine as ‘living wine’ since it still might contain active microorganisms. This is undoubtedly an attractive proposition as long as these microorganisms contribute to the wine’s complexity and don’t cause wine faults, which they unavoidably do, eventually.

Sulphites; A Necessary evil?

Sulphites get bad press but are as essential in winemaking as yeast. Although careless mass-producing wine companies might abuse the substance to produce copious amounts of shelf-stable wine, most reasonable winemakers limit the use of the preservative. Tasting low-sulphite or sulphite-free wine is always an interesting experience — the natural wine producers make exciting wines that are hard to predict. However, at their best, these wines are as good as conventionally produced wine. Unless you’re into oxidative notes in wine or experience adverse reactions to the compound, sulphites are your friends.