Preserving the truth on sulphates in wine
Recently, one of our members, Penny Bamford, got in touch to ask about preservative 220, which you might have seen listed on the back label of bottle of wine. She wanted to know whether it can cause allergic reactions and whether it’s used in organic and biodynamic wine. Tasting Panellist Dave Mavor came to the rescue with an explanation. The main preservative used in wine is sulphur dioxide, which you’ll see on the label as ‘preservative 220’, ‘minimal sulphur dioxide added’ or ‘contains sulphites’. Sulphur dioxide is added in the winemaking process to protect the wine from oxidation and bacterial spoilage. I can tell you that the sulphur dioxide used in winemaking is less than many other products (e.g., dried fruits, some beer, meat, etc.) that we consume every day. It has been used as a preservative in wine since Roman times. And don’t be fooled into thinking that because preservatives aren’t listed on European wines that they’re not present, it’s just that they don’t have the same strict labelling laws as Australia. The amount of sulphur dioxide winemakers are allowed to add is strictly controlled to a limit of 250 milligrams per litre. With such low levels it is unlikely to cause any health issues, however, some people feel they are quite sensitive to it. If that is you, here are some tips:
There tends to be higher levels of sulphur dioxide added to white wines as they are more susceptible to oxidation, whereas the tannins in red wines act as a natural preservative. If you have symptoms from drinking red wine, it’s more likely to be from the histamines.
Age also affects the sulphur dioxide levels in a wine, as it dissipates over time, so if you’re sensitive to sulphur dioxide, go for older wines.
There is less sulphur dioxide used in organic and biodynamic wines. Certification allows 50 per cent of what can be used under conventional standards.
Preservative-free wines don’t have sulphur dioxide added, however, it can also be a natural product of fermentation and is therefore often present even if it hasn’t been deliberately added. Also, without added preservatives, the wine will be very susceptible to spoilage by oxidation, so it needs to be consumed straightaway – which is not a bad thing. You might have noticed the recent emergence of products that claim to remove the sulphur dioxide from your wine. Dave explains that these are simply made up of diluted hydrogen peroxide. While this is a chemical sometimes used in the winery when too much sulphur has been accidently added to a wine, it’s extremely controlled by winemakers with a thorough understanding of the chemical process. Remember that if you add too much hydrogen peroxide to a wine it will go off and you will have spoilt all the winemaker’s hard work!