Oh, this wine contains Sulphites!
The debate surrounding the use of sulphites only came out about 15 or so years ago yet, in this time, it has become increasingly heated and is now a bone of contention for wine lovers and wine critics alike. Vilified by some and fiercely defended by others, this old preservative has come under great scrutiny. So, what are we to think? Look at the label on most bottles of wine and you will see those words: “contains sulphites”. Today, by law, all wines with more than 10mg/l sulphites must state that they contain them. Yet, even without the addition of sulphites, all wines contain traces of it: sulphur is a natural by-product of vinification (hence why labels on natural wines specify that there are no added sulphites).
- Choose the wine with manual harvest.
The mechanical harvest picks up everything and can damage the grapes. So, there may be broken grapes or crushed grapes in the big containers. It is then necessary to add sulphite to prevent oxidation and the spread of bacteria and yeasts. On the other hand, in manual harvesting, the bunches of grapes are selected and they are often put in smaller containers, crates, the risk of breakage is less, so there is less need for sulphites.
- Indigenous yeasts
How the producer conducts the fermentation of his wine, with natural or purchased yeasts. Yeasts contained on the skin of grapes (natural yeasts) or exogenous yeasts (dry market yeasts). If the producer wants to use the purchased freeze-dried yeasts, he will have to eliminate the yeasts present on the grapes. To do this, he will kill them with sulphite. So again, adding sulphites.
- Size of the vineyard
The more the producer processes large quantities of wine, the more handling and the more sulphites he will have to use in order to reduce the risk of contamination. Wine sold in bulk and transported in bulk may also require more sulphur. These wines sold in grocery stores, long on the shelves, exposed to the sun, heat and light must contain more sulphites to keep in good condition.
- Chose the dry wine with a low residual sugar per litre:
The fashion is for round, very fruity wine, such as Yellow Tail. These wines contain more than 4 or 5 grams of sugar. The most sugar there is in the bottle, the higher the risk of re-fermentation. To avoid this, producers put more sulphites in it.
Example: Yellow Tail Shiraz: 12g / L Shiraz Les Jamelles: 5g / L Riesling, Domaine Dopff: 5g / L Chateau Tour Bicheau: < 2g / L
- Organic or biodynamic:
Regulations for organic productions prescribe lower sulphite maximums. It’s 100 instead of 150 g/l for dry red wines. In biodynamics, it is even lower, 70 g/l. In addition, organic producers, those certified AB in France, set even lower limits. In the US for example, the limit is up to 300g/l
- The cork:
The more watertight the cap, the less sulphur they will put in the wine. Thus, wine producers that use screw caps can use less altogether. Some producers even try not to add any or at least have only 30 or 40 grams of sulphites in the bottle at the time of shipment. These are the so-called producers of natural or natural wine.
- Old wine:
Sulphur (sulphur dioxide), SO2, being an odd compound of three molecules (1 Sulphur – 2 Oxygens) it is therefore unstable and tends to transform into the presence of other molecules. It becomes H2SO3 (sulphite) in the presence of water. Thus, in time, it dissipates, dissolves, combines with other elements. In addition, it can also evaporate between the cork and the bottle neck. So, the older the wine, the less sulphites there will be.