June 3rd, 2019 | Technical
These days, a number of people have strong views about the use of sulphur in wine making, indeed, some people have a very low tolerance to it and can suffer side-effects as a consequence. Of course, used at the correct dosage, it is a very effective way to protect wine, preventing oxidation, which is why it has been widely accepted for so long in our industry. The key is using the correct amount. Too little and it won’t really be effective, whilst too much can more or less ‘kill’ a wine completely, so much so that it may never recover.
The presence is always most noticeable when it has just been added. I have no doubt that many a consumer will have received a quick waft of sulphur immediately after pulling the cork. However, given a little time this will dissipate (assuming that the wine hasn’t been over-sulphured)!
A week or two ago we ‘racked’ a few wines from their lees, and transferred them to clean tanks. Any time a wine is moved around the cellar, not only can it lose aroma, but it will also lose a few grams of sulphur too – thereby losing protection at the time it most needs it (during a period of tank storage).
Sulphur is available in a few different forms – one is pure sulphur, which is delivered in tanks and is extremely dangerous. Another is a diluted liquid solution. Usually when a wine requires a significant dose (at the end of fermentation for example) we will use the pure gas form. Whereas when the wine has just been moved and only requires a very small top-up, in this case we prefer the solution form, when we can really be more accurate (the unit of measurement is ppm – parts per million). To put this into perspective, sometimes we may only be adding a few millilitres of sulphur solution to a tank containing 9 or 10,000 litres of wine to move the level by one or two ppm!