Reading wine labels: Contains Sulphites
Should we worry about sulphites in wine?
Every year I pop into RAW, the natural wine fair held in London - and other cities. There is some debate about exactly what a natural wine is and it seems to be the Marmite of the wine world at the moment (you either love it or hate it). Perhaps it may come as a surprise to find that even many so-called 'natural' wines and organic wine have the words "Contains sulphites" (or sulfites) on their labels, words which don't sound very wholesome...
So what are sulphites and why are they in wine?
In wine sulphites are effectively sulphur dioxide (E220) which is a natural by-product (in very small amounts) of the fermentation process; but it is also often added to wine at various stages of the wine-making process as a preservative, to stop oxidation and to kill bacteria. Potassium metabisulphite (E224) may be added as an alternative as it releases sulphur dioxide from grapes for the same purposes.
What levels of sulphites are in wine and how safe are they?
It is as a result of the EU food allergens labelling regulations that those words of warning are required on the label of wines if they contain more than 10 parts per million ("PPM") of sulphites, equivalent to 10 mg per litre, so a very small amount. Sulphites and/ or sulphur dioxide are an allergen for a small number of people who can display asthmatic symptoms when in contact with them. Obviously if you are one of the unfortunate few with that sensitivity you should avoid wines containing sulphites or choose those with very low levels - sulphur detection strips are readily available online.
Reducing sulphites in wine
The good news is that the permitted levels are much lower than they used to be so winemakers have to control contact with oxygen much more tightly and should therefore use sulphur dioxide sparingly.
Harmless sulphites can sometimes be detected by a struck match aroma which some people think adds character to certain wines. If you don't like this aroma in your wine the simple solution is to decant the wine and chill it.
One way to reduce sulphites in wines is to add hydrogen peroxide; this substance oxidises the sulphites and converts them to the inoffensive hydrogen sulphate. There are some products based on food-grade hydrogen peroxide being marketed as a means of removing sulphites from wine but they are not yet available in the UK. The jury is still out though personally I think adding even food-grade hydrogen peroxide sounds far more scary than drinking a wine with safe levels of sulphur dioxide.
What about sulphite-free wines?
If you are one of those people who suffers from headaches whenever they drink wine even in small amounts, I firstly recommend avoiding cheap wine - you may think this is just an effort to tempt you to buy wines with attitude but in general cheaper wines are less well made and more likely to have been adjusted with additional sugar, alcohol, oak flavourings etc. It may also be worth trying to avoid oaked wines and grapes particularly high in tannins like Cabernet Sauvignon, Touriga Nacional and Nebbiolo as my theory (not scientifically proven) is that the tannins which develop in wine aged in oak can be the cause of headaches for some people.