The truth about wine preservatives and additives

Preservative 220 (sulphur dioxide, or SO2) and preservative 200 (sorbic acid) are substances that may be added to wine as a protection against oxidation and bacterial spoilage. This is the same kind of preservative used to protect dried fruit sold in supermarkets. Sulphur dioxide is an extremely effective preservative and disinfectant that has been used in winemaking for thousands of years, with writers such as Cato and Pliny mentioning its value in the winemaking process.

Do reds affect you more than whites?
Many wine drinkers think that they have reactions to certain wine styles. For example, you might hear someone say that they can’t drink red wine because of "all the preservatives", yet white wines don’t have the same affect. What they probably don’t realise is that in most cases there are more preservatives used in making white wines than red wines.

There are other substances in wine that may aggravate allergies. Oak-derived tannins can provoke an allergic reaction by promoting histamine production, causing headaches – it can be like getting a hangover while you’re just starting to drink the wine! Oak is widely used in red winemaking, and to a lesser extent some white wines.

One and a half tablespoons in every 1,300 bottles of wine
In winemaking, addition of preservatives can take place at several stages, from when the grapes have just been picked right through to bottling of the wine. Because the substances are used in such tiny quantities, they are measured in parts per million (ppm). Here in Australia, addition is allowed to the maximum level of 250 ppm for dry wines, up to 300 ppm for sweet wines. This is still a miniscule amount, equivalent to just one-and-a-half tablespoons per 1,300 bottles of wine. By comparison, sulphur dioxide is often used more liberally in preserved fruit such as dried apricots, which are allowed up to 3,000 ppm.

An interesting test of someone’s perceived intolerance to sulphur dioxide in wine is to ask whether they get the same symptoms from eating dried apricots. If the answer is no, it’s a fair indication that their allergy could be caused by something other than sulphites.

Few winemakers use more than 120 ppm of sulphur dioxide in white wines, however cask wines, particularly the sweeter styles, can often hit the 300 ppm limit. Red wines are usually given 50–80 ppm for bottled wine, up to 80–110 ppm for cask wine. So if you’re concerned about preservative levels in your wine, it would be advisable to stick to bottled wines – and drink dry rather than sweet styles.

Wine is a natural product that contains nothing more than comes from the grapes or results from the fermentation process and influences from the winemaking process, such as malolactic fermentation (where the sharp malic acid is converted to soft lactic acid) and oak maturation. Even when it’s bottled, wine is a living organism that evolves with time. The role of preservatives and additives is to ensure that the wine remains stable and tastes clean, fresh and palateable for its entire lifetime.