Sulphites in wine – are they really bad for us?

French fries and dried mango contain far more sulphites than wines, so surely a glass or two of vino can’t do much harm
Asthma sufferers though are especially sensitive to the chemical compound

Nellie Ming Lee

Published: 9:30pm, 27 Jun 2019

Why you can trust SCMP

The “contains sulphites” warning on wine labels can cause alarm among consumers. But those sensitive to the chemical compound – such as asthma sufferers – might be surprised to learn that wines contain much lower levels of sulphites than processed foods such as jams, dried fruits, cured deli meats, canned soups and French fries.

Sulphites are used to prolong shelf life and preserve colour. As a by-productof the fermentation process, they are naturally present in wines but in low levels. More sulphites are added to prevent oxidation and protect wine from bacteria and yeast, which can turn the liquid into vinegar. This practice dates back to the Romans, who burned candles in amphorae (conical-shaped jugs) before filling them with wine. Sulphites are also used to sanitise winery equipment, such as fermentation tanks, hoses and valves.

Under current labelling regulations, wines sold in the United States and European Union that contain more than 10 parts per million (ppm) are required to carry the “contains sulphites” warning on the label. However, even without added sulphites, the fermentation process can result in a wine that has more than 10 ppm.

Wine labels do not specify how much sulphite is present in a bottle, but it is usually somewhere between 20 and 200 ppm – very low compared with dried fruit, which can have from 500 to 3,000 ppm (among the worst are dried apricots, which are heavily dosed during the drying process to retain their orangey hue).

Red wines typically contain less sulphites than white wines. Photo: AFP

Sulphites in red wines range from 50 to 75 ppm – which is lower than whites, because tannins are a natural stabiliser and almost all reds go through malolactic fermentation as well, reducing the sulphite content.

While dry white wines contain about 100 ppm, whites with higher acidity, such as sauvignon blanc, have fewer sulphites than low-acidity wine, such as pinot grigio.

Sweeter wines, such as sauternes and ports, contain more sulphites, which are necessary to prevent secondary fermentation in the bottle.

Many natural and organic wines are made without additional sulphites. A wine that is labelled “made from organically grown grapes” will have some added sulphites, whereas “organic wine” will not. The latter has a short life, so is best consumed young.

If you are among the unfortunate few who tend to get a headache after drinking wine, it is probably due to histamines, alcohol or tannins rather than sulphites. Tyramine, an amino acid found in tannins, triggers migraines, according to research by Dr Frederick Freitag, a headache specialist and an associate professor at the Medical College of Wisconsin, in the US.

Alcohol intolerance – symptoms include a stuffy nose and turning red in the face – is a genetic condition wherein the body is unable to break down alcohol. There is no cure.

Histamines in wine can cause an allergic reactionsimilar to the symptoms of hay fever – shortness of breath, a tightness in the chest and itchy eyes. White wines have significantly lower levels of histamines (3 to 120 ppm) than reds, which can go from 60 to 3,800 ppm.

Sulphites can be easily detected by a trained nose – they smell like a freshly lit match or a cooked egg. This can be remedied by chilling the wine and decanting to allow these aromas to dissipate before sipping.

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