This article tries to shed some light on farming & wine making practices in relation to the use of the preservative sulphur dioxide (referred to in this article as 220 or sulphur) and attempts to clarify some of the confusion in wine labelling. I say attempts because there is plenty of grey area when it comes to preservatives, organic, biodynamic and conventional farming. Please let me know if you think I’ve missed anything!
Sulphur dioxide is a natural substance (meaning it occurs naturally in nature, and in human bodies also) used safely for centuries to control plant pathogens and mites. As an active ingredient, sulphur dioxide is the leading pesticide Australian viticulture. It is a very important and effective tool for managing powdery mildew — one of the major diseases affecting wine grapes. It is also used widely in conventional winemaking to prevent spoilage & oxidation. If added in winemaking it must be declared in a statement such as preservative 220 added. Significantly, if it’s only used in the vineyard, but not in winemaking it doesn’t have to be declared on the label. This is due to the regulations around withholding periods outlined in the industry ‘dog book’. Human exposure to sulphur can cause eye irritation, breathing difficulty, and skin irritation and anecdotally (ahem!) appears to worsen hangovers.
Conventional Grape Growing
Making money from vineyards these days is very, very precarious due to both external market changes and the pressure of agricultural consistency. This is the motivation for most to stick with using standard viticultural practices which involve preventative & reactive chemical treatments. The traditional/conventional way of thinking is that if grapes are your livelihood, you’ll do whatever you can to save them from going bad, increase yields and protect from disease. And the use of fungicides, herbicides & pesticides are options for this type of farming. It all sounds very toxic, so bear with me. It’s important to note that all of these applications are very closely regulated and are approved, in fact – to a point where producers don’t actually need to state the use of these chemicals on the label because they are considered safe. This doesn’t mean I support these methods but they are approved by the AWRI.
Conventional wines are treated with sulphur throughout the winemaking process to prevent oxidation and preserve the wine from spoilage. Levels in conventional wines vary: the maximum allowed level in finished white wine is 250ppm (parts per million) and 400ppm for dessert wines. Reds tend to be lower because the tannin in itself can act as a preservative. Conventional producers are not required to state the Xppm on the label, just a general statement such as Preservative 220 Added. As much as 10ppm will occur naturally as a by-product of fermentation, so it is safe to assume that if you have a sensitive allergy, wine is not an option (try sake – it’s preservative free!). Generally speaking, preservative free wines have a shorter shelf life – however there are exceptions to this. Sulphur levels tend to reduce over time as the wine ages.
Sulphur as a preservative is effective and is widely used in food also – see the table here at the bottom of the page which provides an overview for Australian food. It’s worth noting than any consumable product in Australia which has levels of 10ppm or less of sulphur does not require a statement on the label.
What does preservative free mean? This unregulated statement is independent of organic & BD farming – as it only refers to the actual winemaking. It means there was no sulphur added in the winemaking process – so levels should be under 10ppm.
Organic Grape Growing
As much as there is motivation to stay conventional, there is also plenty of motivation to convert to organic farming. Organic farming focuses on soil health and prohibits any additive to the vineyard which doesn’t already occur naturally. So, in organic viticulture, using sulphur & and copper sulphate (as sprays) are actually allowed because both of these compounds occur naturally – even though they are manufactured to use in vineyards. No other manufactured additives are allowed, and therefore organic vineyard management is very focused on a natural ways to maintain vineyard balance including mulching, cover crops & compost.
These principles follow through to making wine – with no chemical additives except for low levels of sulphur which acts as a very effective anti-oxidant. Significantly, for people who have reactions to sulphur, just because something is organic, doesn’t mean it’s preservative free. Depending on who certifies the individual products, organic wine is generally allowed 50% of the sulphur levels allowed in conventionally made wine, which normally results in levels under 120 ppm. As a comparison, commercially dried apricots often show levels of up to 2000 ppm.
There are seven organisations (seven! no wonder we’re confused) who govern certification and each of these organisations have slightly different rules. If a wine is certified it will be organically grown & organically made, however the actual ppm levels can differ. It might have no sulphur added (under 10ppm, which may carry sulphur free type statement on the label) , or contain levels up to 50% of what is allowed in conventional wine (which still calls for a standard ‘220 added’ statement). If it’s not certified things become very vague: it could be organically grown, but made conventionally – or the other way around. It could be anything really, so it’s up to you to find good information & buy from producers you trust.
To add to the confusion, many producers use organic & BD principles in their vineyard yet ignore certification because it is costly and requires an extraordinary amount of paperwork. They might use statements such as ‘sustainable viticulture’, ‘managed without chemicals’, ‘environmentally friendly management’. These terms are also all unregulated so the trouble is, what do you trust? If you know the producer then go for it, if not – buy certified.
Biodynamic Grape Growing
BD farming methods are globally recognised as the pinnacle of establishing & maintaining vineyard health. BD farming decisions are conducted according to the moon cycles and a series of natural preparations are used to maximise vineyard balance, no additives are used. To quote certified BD producer Cullen (Margaret River) ‘Biodynamic relies on a series of preparations based in mineral, plant and animal substances rather than the traditional potentially toxic chemicals and sprays. In the Cullen Vineyards, this involves firstly the enhancement of the soil structure through the addition of homeopathic preparations, specially prepared composts and various fish and other emulsions and also the use of nitrogen-enhancing cover crops. The resulting increase in humus in the soil leads to greater microbial activity and improved aeration and retention of moisture around the roots of the vines’. BD certification is again a long, expensive process and so there are many vineyards out there applying these principles without seeking certification.
To learn more about BD grape growing, check out Daniel Honan’s work over at THE WINE IDEALIST.
BD winemaking is an extension of BD grape growing – and although there is no official text as there is for farming it seems nonsensical to unravel the positive work of BD farming with conventional winemaking. Certification (through NASSA, however other certifying organisations do vary) requires a maximum of 20ppm added sulphur – which is generally added at bottling. Some will have no sulphur added.
Another winemaking philosophy called ‘natural’ winemaking often will go hand in hand with BD grape growing. There is a growing movement of these style of wines which in a nutshell ignore traditional additions and subtractions throughout the winemaking process. So, no commercial yeast, no acid or tannin additions, no new oak, no fining or filtration and sulphur added only at bottling in low doses.
A quick summary:
- Conventional wine: Generally under 250ppm in still wines, must have Preservative 220 Added statement if above 10 ppm
- Certified Organic: Generally up to 50% of conventional wine levels, depending on certification & wine type. Must show statement Preservative 220 added if levels are above 10 ppm
- Certified Biodynamic: Varies by certifying organisation but generally under 20 ppm. If above 10 ppm must show statement as above.
- Sulphur Free/No Preservatives added statements can be independent of any organic of BD certification, and apply to any wine with less that 10 ppm.
So, how to know what to buy? Firstly, use apricots or other similar products to decipher that the reaction you have from wine is actually from sulphur – it could be from histamines or simply just the alcohol. For those who choose to drink wines with low sulphur: buy certified organic or BD wines, or buy from a non-certified producer you trust who has made a statement on their label of no/low preservative added. For those who just want to support organic & BD producers – again, look for certification but if you trust a non-certified producer that is almost the same thing!
I’ll add a directory of where to buy these wines soon in the venues & stores page.
Happy drinking! Clare