There is a lot of debate about use of sulphur in grape and wine production. A recent article in Decanter raises the issue once again as a major retailer pulls a quantity of stock due to elevated levels of sulphur (http://www.decanter.com/news/wine-news/583979/majestic-pulls-chablis-over-health-fears). I have always been cautious about the use of sulphur ensuring that the minimum possible levels were used in my wines. Having said that, clearly sulphur is a natural occurring element found in many plants, soils, rocks and living things. It is, in fact, essential for the growth and functioning of all plants including vines. Recent research has even found that sulphur dioxide evokes a large scale reprogramming of the grape berry increasing the antioxidant levels, anti-fungal levels and biotic defence responses (Assistant Professor Michael Considine 2013, ‘Investigation of Respiratory Control in Dormant Grapevine Bud’, Grape & Wine Research & Development Corporation). There is little debate about the use of sulphur on vines and even certified organic producers are permitted to use some naturally occurring substances, such as sulphur.
Sulphur dioxide is used in the wine making process and as an additive in the wine to act as a preservative, eliminating spoilage by bacteria and as an anti-oxidant. Many would argue that it is an essential ingredient of merchantable wine to preserve freshness and quality. Sulphur has been used as a food preservative since roman times and it’s use is well understood, monitored and regulated.
So whats all the fuss about?
Firstly there is the esoteric argument that these wines are not ‘natural’ because they contain an additive. I will not enter into this debate, at least for the moment! Then there is the allergy debate where many people claim that they experience allergic reactions to the sulphur in wine and especially that it triggers asthma attacks and headaches. At prescribed levels used in wine, which are below the sensory threshold, there should no ill-effects on the respiratory system or cause of headaches. The ‘Wine Doctor’ writing on Wine & Health (http://www.drnorrie.info/html/article_allergysideeffectshangovers.html) states that either the histamines or tannins in the wine are more likely to be the cause of allergies from consumption of wine. As a past sufferer of asthma, I vividly remember an attack being triggered when I eat a quantity of dried apricots (preserved with sulphur). Excessive use of sulphur can be cause of health issues and hence my own concern for lowest possible levels of use in my wines. Also different people have different sensory sensitivities and a heavy use of sulphur can quite often detract from the enjoyment of wine. Putting aside the natural wine issues, it seems to me that the over-use or incorrect use is the problem not sulphur itself.