Researchers at the viticultural research station at Rancho de la Merced in Jerez have proved that Vineatrol, an extract from the shoots and leaves pruned from vines, can replace sulphur dioxide (SO2) as a preservative in wine.
SO2 has been used for centuries in virtually all wines (and many foods) for its antioxidant and antimicrobial properties, but many people feel it causes allergic reactions despite proof that barely 1% of the population are likely to be affected. Wines containing over 10 milligrams per litre (which is nearly every wine) must put “Contains Sulphites” on the label, even if that SO2 is a natural result of fermentation by yeast and not added. In any case use of SO2 is strictly controlled by law.
The lead researcher in this project, Emma Cantos Villar, says that the scientific community is looking for an alternative to SO2 and Vineatrol seems to do the job without affecting aromas or flavours in wine, while SO2 can occasionally give a slight sulphury aroma like a struck match. This extract is rich in polyphenols called stilbenes which have good antioxidant and antimicrobial properties. Other studies have shown that they also have health benefits with properties which inhibit cancer and diseases of the cardiovascular and nervous systems among others. It can even lower bad cholesterol.