Last week we had a quick overview of organic, biodynamic and preservative free wine (have a squizz here) but one topic deserves a bit more attention - the danger (or not) of preservatives in wine.
Generally, there are two preservatives used in wine production, designated by the food additive codes of preservative 220 and 300. There is another that sometimes pops up with the code of 224, but generally 220 and 300 are the most common.
Of the two, preservative 220 - sulphur dioxide (SO2) - is almost omnipresent, found in nearly every wine on the market. 300 is absorbic acid, which is technically an antioxidant and not a preservative, and only found in white wines. Ascorbic acid is less widely used than it once was, but often pops up in young, crisp white wines. You probably know absorbic acid by its much more marketable name... Vitamin C!
So obviously we're not too worried about adding vitamin c to our wine. That leaves sulphur dioxide as the major focal point.
SO2 is one of the most used preservatives in food production, with it's ability as an anti-microbial and antioxidant agent revered in many industries, particularly fruit, bread and many canned foods. Sulphur was first used in wine production by the Romans who worked out that burning a sulphur candle in wine vessels helped to stop wine turning into vinegar.
Since then sulphur dioxide has become a natural go-to, with it's benefits thought to balance out the negatives (which on the production side include a risk of hydrogen sulphide development and the binding of colour).
More recently, however, there has been considerably backlash against all food additives, with the result a push towards 'preservative free' wine.
As we touched on last week, the whole idea of preservative free wine is a misnomer, as sulphur dioxide is produced as a natural biproduct of fermentation (hence why it should be called 'no preservative added wine').
But just how dangerous is sulphur dioxide, added or not?
Sulfites (the salt of SO2) are a noted allergen, but really as Dirk Vermeersch notes, it is almost impossible to have an immune (allergic) response to it!
Further, the concentration in wine is miniscule. Concentrations (in Parts Per Million) of sulphur in wine are between 25-40PPM, with sweet wines allowed to circa 125PPM. Organic wine is required, (in Australia at least) to have concentrations on the lower end of the scale, but important to note that organic wine is not necessarily 'no preservative added'.
Compare that to dried fruit which is 10x that amount (1250PPM)! There is more sulphur in a handful of dried apricots than a whole bottle of wine! Concentrations in canned goods, bread etc are also higher than wine. If you can eat tinned spaghetti you are (effectively) not allergic to sulphur!
So what causes the red wine headache? Or other reactions to wine? Our mate Dirk believes that bio-amines (a chemical plants use to repel predators) are one such cause.
Do you know what the biggest cause of most reactions is though? You're not going to like it... Alcohol itself!
Alcohol is a known poison (not just an additive) and is found in much higher concentrations (14.5% by volume is a lot!) than any additive and causes everything from rashes or hives right through to complete renal failure, not to mention that it also dehydrates, which only enhances the headache...
Further, there are a whole host of other (natural) compounds in wine that may cause reactions in certain people. Histamine and Tyramine, for example, are varying constrictors and dilators (which can cause hot flushes). Even the natural compounds found in oak barrels can upset some people.
Ultimately we still don't know exactly what causes reactions from wine in certain people, but we do know one thing - preservatives aren't likely to blame. Drink on folks!