I am often asked why nearly all wines contain sulfites and whether it is really necessary. The reason that most wines have a small amount of sulfur is to protect them from spoilage, predominantly from bacterial attack but also from oxidation. It is used both as as a preservative and an antioxidant so that the wine can be kept for a reasonable length of time without deteriorating. Sulfites are also introduced to stop fermentations at a desired time.
Yeasts are naturally occurring in grapes and therefore are in wine as well. It is these yeasts that consume the grapes sugar during fermentation producing bi-products of carbon dioxide and alcohol. When the fermentation finishes most of the yeast cells will die and be removed from the vessel by racking (pumping liquid off a sediment), but a few will remain within. Without the addition of a controlling amount of sulfite, the wine could soon develop off-flavours and turn ‘musty’ very quickly.
Winemakers know how much sulphite to add after analysing their wines, and should the addition be excessive this would be very noticeable on the nose and overall flavour in the glass. The secret is to make your wine in as hygienic an environment as possible, preferably in a stainless steel vessel, and monitor the wine for yeast or bacterial growth regularly – then take action straight away.
Sulphur is a common element which occurs naturally in foodstuffs, nature and the human body. The term ‘sulfites’ cover the use of sulfur based preservatives, sodium and potassium metabisulfite as well sulfur dioxide gas (SO2). In home winemaking, Campden tablets are the common sterilizing agent and antioxidant (these tablets contain about 60% SO2).
So, what is the connection between headaches and sulfites in wine?
It has been said that headaches are caused by sulfites in the wine but there is no direct proof of this. In fact most headaches occur from over indulgence of alcohol which then causes dehydration. If you were one of the tiny percentage of people who has an allergy to sulfites, you would suffer serious breathing difficulties, rather than headaches, by consuming any product containing them. There are several studies linking sulfites to the cause of asthmatic and respiritory problems.
A few facts about sulfites in wine:
- Nearly all wines contain sulfites which means that most winemakers from leading wine producing countries add sulfites into their wines.
- A very few organically produced wines will be completely free of sulfites. This is a requirement for an organic wine. The main drawback is that the wine will not keep for long so will have to be consumed almost immediately.
- Sulfites in wine do not cause headaches, there is something else in red wine that does, but that has yet to be be fully discovered. The bitter tasting tannin in red wine is sometimes blamed for causing headaches.
- There is law in most countries governing the maximum amounts of sulfites allowable in wine. In some of these countries this information must appear on the label.
- A team of scientists from Spain have found that by using ozone rather than sulfites, this has resulted in high levels of antioxidants being retained in the wine and so guaranteeing quality
Therefore, in order to avoid headaches and the dreaded migraines, the simple answer when drinking wine is to consume less of it while at the same time taking in copious quantities of water (glass for glass if you can). Drink wine with food and appreciate both is my advice!