Right in the middle of the festive season, it seems only fitting that we talk about wine! You may have drunk many a glass of fine vino over the Christmas period so far, but there is still one more night to go, when drinking wine is a must, the night we celebrate out with the old and in with the new, we make resolutions of how life will change in the coming year, we look back over the past 12 months and ponder as we look forward to the next 12 with excitement, New Years Eve!
So let’s talk about wine, its properties, its’ quality and why going organic for our favourite tipple is a good choice.
Preservatives and Wine
Alcohol is a natural preservative, however most wines will contain an added preservative to prevent bacterial spoilage and protect against oxidation. This preservative is a form of sulphur and can be added at any stage of the wine making process. The main preservatives used in wine are 220 (sulphur dioxide) and 224 (potassium metabisulphite).
Sulphur is naturally reactive and “binds up” with potential spoilage compounds in the wine to protect its longevity and cellar life. Sulphur that does not “bind up” stays in the wine and eventually becomes bound up with air traces or other contaminants which can then cause the wine to spoil. For health and allergy considerations it is the “free” sulphur that is the main health concern. Under organic certification, the sulphur level will usually be less than half that of the “normal” level of preservative added to a bottle of wine. (This will differ depending on the wine and the certifying body).
Even wines that have no sulphur dioxide added can contain sulphur as sulphur dioxide is a natural product of the fermentation process. However, in these cases the sulphur will be “bound up” in the wine and therefore not in a free and active state. The term “preservative free” wine will indicate that no sulphur has been artificially added to the product.
Can you cellar preservative free wine?
Some people say that you can't cellar a wine that has no preservative added, however, it really depends on the quality & concentration of the fruit and the handling of the wine during the winemaking. Just like conventional wines, look for a wine that has been made for long-term cellaring. Speak directly to the winemaker if possible, they will usually the best person to ask about this. White wine would be much harder to cellar long term (7+ years) because it doesn't have the tannins that red wine has and is usually lower in alcohol than red wine.
Why does the level of preservatives in wine differ in each bottle?
There are a number of things that will affect the amount of preservatives added to a bottle of wine. Here are a few for you to consider:-
- Alcohol is a natural preservative, therefore higher alcohol content wine will need less sulphur added
- Tannins are also natural preservatives and levels are higher in red wine (extracted from the skins of the red grapes during fermentation). Oak tannins will also be found in wines which have spent time in oak barrels.
- Well handled grapes and wine will have less exposure to the elements and will therefore require less preservative to be added. Healthy grapes will have a higher acid level and therefore need less sulphur, as well as clean equipment and bottling procedures giving less chance of spoilage.
- Believe it or not the screw cap is the best seal for preserving your wine. It may be less romantic when you are opening your bottle of fine shiraz, however, the cork is more permeable and therefore has a higher chance of spoilage, for this reason winemakers may add more sulphur to cork capped wines.
- Wines housed in casks will also require higher sulphur levels due to the nature of the packaging.
“There is nothing that has taught me more about winemaking than the effort to make wines free of sulphur dioxide. I reckon that the production of one preservative-free wine should be mandatory for all winemakers. The capacity to produce a high quality PF wine tells a story about ones technique”.
Winemaker of “Happs PF Wine”, Margaret River, WA