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What are sulphites in wine – and do they matter?

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What are sulphites in wine – and do they matter?

There’s more to wine than just grapes, yeast and sugar – sulphites also play a vital role in the winemaking process. But what exactly are they, and what part do they play in winemaking? Do they really cause wine headaches?

Read on to learn everything you need to know about sulphites in wine.

What are sulphites?

Sulphites – called sulphur dioxide or SO₂ – are chemicals in many foods and drinks, including wine.

Different wines have different amounts of sulphites. Grape variety, fermentation conditions and the winemaker’s choices can affect a wine’s sulphite level.

Sulphites are potent antimicrobials, helping prevent spoilage and oxidation.

Even if winemakers don’t add them, sulphites are still present in wine because yeast naturally makes small amounts during fermentation. So all wine contains some sulphites.

Using sulphites in wine is an old practice going back to Roman times.

The Romans discovered that burning sulphur candles inside wine containers kept wine fresh. By the 1700s, this was common practice. Today, winemakers add just the right amount to preserve their wines’ integrity.

Are sulphites bad for you?

Most people can consume sulphites without suffering any reactions. Only a few people, particularly those with asthma, may be sensitive to them.

Despite what many think, sulphites don’t cause headaches. Histamines, which are natural chemicals in grape skins (especially red grapes), are more likely to blame.

If red wine gives you a headache, try exploring white wine or rosé.

When drinking red wine, remember to drink water, too. Water will not remove histamines, but it can help with dehydration headaches.

What role do sulphites play in wine production?

Sulphites are potent compounds that safeguard your wine’s character by blocking harmful bacteria and preventing chemical changes that could dull flavours or create undesirable bitterness.

Wine is susceptible to oxidation, which can rob it of its vibrant flavours and enticing aromas. Sulphites create a protective barrier against oxygen, protecting the wine from excessive exposure and ensuring it stays lively and enjoyable.

Sulphites also help keep wine stable during shipping and storage.

Do all wines have the same sulphite levels?

No, sulphite levels differ a lot between wines.

The naturally occurring sulphites that form during fermentation aren’t controlled and can differ between wines. Although winemakers must adhere to strict regulations when adding sulphites, no single amount is used for all wines.

Sweet wines usually have more sulphites than dry wines. Additional sulphites may be added to prevent unwanted fermentation of residual sugars and to protect against spoilage during storage.

Dry red wines typically have fewer sulphites. Their extended contact with antioxidant-rich grape skins during fermentation provides natural protection against oxidation, discolouration and spoilage.

Wines with higher acidity need fewer added sulphites because the acid itself helps protect against bacteria.

Some winemakers add very little or no extra sulphites. These wines might be labelled “low sulphite” or “no added sulphite,” though this labelling isn’t mandatory.

According to the Australian Food Standards Code, wines containing 10 parts per million (ppm) or more of sulphites must say ‘contains sulphites’ on the label.

How do I reduce my sulphite intake?

Certain wines naturally require fewer sulphites. Red wines, with their natural antioxidants, often need less SO₂, and wines from small producers who adopt minimal intervention techniques are also good options.

Fresh, early-drinking styles generally have lower sulphite levels than wines aged for longer periods.

Organic wines have stricter sulphite limits than conventional wines, while biodynamic wines adhere to similar principles. Natural wines often have little to no added SO₂, making them more sensitive to storage conditions.

These wines can be a good starting point if you want to reduce your sulphite intake.

What do sulphites taste like?

Sulphites don’t usually change how wine tastes, nor do they have a unique flavour themselves. Winemakers add them in tiny amounts, following strict rules, so you rarely taste them.

Occasionally, if a winemaker uses too much SO₂, you might smell something like a burnt match. This smell usually disappears if you let the wine breathe for a while.

Sulphites in wine – the bottom line

Sulphites play a vital role in winemaking, safeguarding freshness, preventing spoilage and ensuring the wine’s stability. While some people worry about sulphites, only a tiny percentage of people are sensitive to them.

For most wine lovers, the benefits of sulphites greatly outweigh any potential drawbacks. For most, the key to enjoying wine without any unwanted effects is to enjoy it in moderation and stay hydrated, so you can fully appreciate your favourite glass of red, white or rosé.

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