Why, in Australia, do most wines have added sulphur dioxide? In Europe, added preservatives are banned. I suffer from migraines.

—K.P., Baulkham Hills, NSW

Sulphites are used as a wine preservative all over the world, but Europe doesn’t have laws requiring disclosure on labels as Australia does. This leads some people to assume European wines don’t contain sulphites, which isn’t true. Their wines contain similar amounts to ours.

Furthermore, there’s no scientific evidence that sulphites in wine cause headaches, although those with a sulphur allergy are an exception – but this is thought to be a tiny percentage of the population.

There are, however, strict limits on how much sulphites are allowed in various foods.

Sulphites, aka sulphur dioxide or SO² (preservative 220), are used to prevent oxidation and stop undesirable microbes from spoiling wine. White wine without sulphite quickly turns brown and stale. So it’s a vital quality measure.

I don’t know of anywhere that has banned sulphites. Even in the organic and biodynamic protocols, SO² is permitted, albeit with lower maximum limits. There are, however, plenty of winemakers who make wine – particularly red wine – without adding SO² (they can’t call it sulphur-free because some SO² is produced by the yeasts during fermentation).

Most wine drinkers don’t have a sensitivity to sulphur, even chronic asthmatics I’ve known, but it’s probably wise to avoid those wines with the most SO² in them, such as sweet whites and wines packaged in a pouch or cask (bag-in-a-box). And red wines usually contain less SO² than whites.

The good news is, there are several inexpensive products you can add to your glass of wine to nullify the SO², such as SO2GO, Just The Wine and Pure Wine Drops. Some retailers sell them; if not, you can easily buy them online.

Finally, some drinkers may indeed have an allergy to sulphites, but we shouldn’t automatically blame the preservative. A headache could be caused by the alcohol, an allergy to the alcohol, dehydration, the food you ate with the wine or something else entirely.

Got a drinks question for Huon Hooke? thefullbottle@goodweekend.com.au