All wines contain sulphur, but some less than others, help is on the way
Almost all wines contain sulphur. This is not only because most winemakers add sulphur to stabilise the wine and make it more long-lived. It is also because during fermentation sulphur is produced. The yeast that converts sugar to alcohol, carbon dioxide and other various substances also produce sulphur, as a by-product of its metabolism. Sulphur is therefore actually a “natural” ingredient in wine.
This being said many (most, if not all) wineries do try to keep the sulphur content of the wine at a level as low as possible. The winemaker does not need to be an extremist natural wine enthusiast to do so.
A new yeast strain, called Lalvin ICV Okay (why this odd name?) has been launched, which can help minimising the sulphur in the wine. Thanks to the mapping of the genome of Saccharomyces cerevisiae researchers have managed to find the genes responsible for sulphur production.
Jessica Noble is the name of the scientist who made the ground work that was further developed in a collaboration between l’Institut Coopératif du Vin (ICV), Lallemand (a company in the wine yeast industry), the school SupAgro in Montpellier and the French agricultural research institute INRA.
Lalvin ICV Okay produces significantly less sulphur, it is said, but also less ethanal (acetaldehyde, which binds sulphur), which means that the wine maker needs to add less sulphur at bottling.
Read more about this yeast breakthrough on Vitisphere.