Italian Organic Wine and Sulfites – Three Different Approaches

It is impossible to talk to organic winemakers without breaching the subject of sulfur dioxide. Each winemaker has their own opinion, theory and practice. How sulfur dioxide can be limited depends on the wine type, the company set-up and many other factors. In turn, making low-sulfite wines will influence production and sales, meaning the whole company has to adapt to its chosen policy. Producing low-sulfite wines is not a case of doing less, but of doing much, much more. Here are three winemakers, with three different stories, I spoke with while doing my research in Italy.

Valli Unite, Piemonte


Ottavio is one of the founders of the organic cooperative Valli Unite in the North-Western region of Piemonte. While the cooperative produces various organic foodstuffs, wine sales have always been the backbone of its economy; a natural choice considering the long winemaking traditions of the region. Having consolidated family vineyards of the founding members, the cooperative begun wine production in the early eighties. In contrast to the post-war generation of their parents, the founding members rejected \’chemical\’ agriculture, and went back to pre-industrial traditions of vine cultivation and winemaking, producing organic wines before this category became recognised either by consumers or by regulators. Concerned about their own health and that of the environment, they sought to limit to the use of chemicals, including sulfur dioxide. Those early days were not easy, however, and Ottavio recalls a decision he had to make regarding his vinification methods:

Ottavio: You need some compromise with the idea of completely \”natural.\” I can say that I made wines without sulfites until \’91, without added yeast until \’98; and then I had a whole series of problems, and I understood that I was putting the economy of the cooperative at risk. I was not able to sell, so all this was on my shoulders.

At a certain point I asked myself if I was not risking too much, so I took some steps back which was something \”ugly\” for me. Something that made me disenchanted a bit with the work of the cantiniere. I was not able to make wines without sulfites, but at the same time they became calibrated, exactly like they should be. So I started to say, what I guarantee is a wine that is within organic norms and we do not add anything that is not allowed by organic rules. But things, yeast, and so on, we put in.

The problems Ottavio alludes to could be secondary fermentations in the bottle, unpleasant odors in the wine and high quantities of sediment. All of these are officially recognised as faults in wine certification and control, and are also potentially off-putting to consumers. Uncontrolled microbial activity impact what is generally recognised as \’quality\’ in wines. Many of these unwanted developments can be avoided by the simple addition of sulfur dioxide – thus \’giving in\’ and compromising the idea of completely natural; a move which made Ottavio disenchanted with his work. However, the presence of sulfur dioxide assures the economic survival of the company, and the market place has the upper hand in the end. Sulphur dioxide gives Valli Unite the possibility to take part in the international wine market.

Terra D’Arcoiris, Tuscany

There are consequences of not \’giving in\’ to sulfur dioxide. You must organize your sales network in a different way. In the early 80s, Paola Leonardi and her partner Walter Loesch set up a biodynamic wine and fruit producing company Terra D\’Arcoiris in Tuscany. Today their company is used as a shining example of biodynamic agriculture by its international certifying body Demeter. \”It\’s me who should be certifying them, not they who should be certifying me\”, laughs Paola, and there certainly is a truth in this. Paola and Walter are on what many consider to be the extreme end of organic production. They not only avoid pesticides, herbicides or fertilisers, but they also use no manufactured yeast, and limit the use of sulfur dioxide. This approach is not without its burdens.

Paola: The only thing that we put into the wine, and this is in extremely small doses, is sulfur dioxide. As far as the rest is concerned, we don\’t do anything. Every month we take samples of our wines and send them to France to be analyzed. We only add sulfur dioxide if it is necessary, while keeping the wine all the time under control. Nonetheless, some wines have a problem of brettanomyces, exactly for this reason. By keeping the wine for so long in wood, the risk of brettanomyces is very high, especially if you don\’t protect them with sulfur dioxide. And we work this way, always within the limits of risk.

In 2001 our red label had brettanomyces. We did not sell it to the distributors, we sold it all in direct sales. The strange thing about brettanomyces is that it occurs in some bottles and not in others not. So, not being able to guarantee the absolute cleanness of this wine , we work in this way, having the direct sales mechanism. Our clients do not risk anything: they always try our wines, and there are those who do not note the taste of brettanomyces. Direct sales allows us to figure out the taste of the consumer and understand that you can educate people about a different taste; which is a natural taste.

Using low levels of sulfur dioxide runs a considerable risk for Paola. Brettanomyces is a wine spoilage yeast, and its presence in wine is considered a fault. It is known to produce an unpleasant \’stable\’ smell and is generally an unwelcome microorganism. It is impossible to sell this kind of wine to a distributor. Wines with low amounts of sulfur dioxide are more vulnerable, and have trouble surviving long journeys on the back of a truck, where they are exposed to changing temperatures.

International export is even more problematic, and even locally no one wants to find themselves with a stock of undrinkable bottles. Terra D\’Arcoiris, however, has found another path. The direct sales network they have been building up for years allows them to sell the risky, problematic wines face to face. Paola takes it upon herself to educate her clients about the wines she\’s selling, and she accommodates the risk of low sulfur wines by opting out of the impersonal marketplace where stability is much more of an issue.

Perlage, Veneto

The Animae Prosecco is considered by Ivo Nardi, owner of Perlage, the culmination of the scientific and product development of his company. It is a unique product: the first sparkling white wine in the world to be produced without any addition of sulfur dioxide. This additive-free wine could be considered the epitome of organic production. Indeed, this is how Ivo, the originator of the idea, sees this unusual product.

Ivo: Perlage did the first organic Prosecco, then we did the first biodynamic Prosecco. The natural evolution was that this biodynamic Prosecco should also be a Prosecco without sulfites. A product that would be as complete as possible, without chemical interventions. This has been a great personal satisfaction. On a scientific level it was a real victory, a sparkling wine which is as natural as possible.

While being \”as natural as possible,\” this wine has little to do with tradition and breaks a number of conventions. It came into being through a series of complex cooperation involving laboratories, machines and microorganisms.

The first challenge was with the yeast strain used for fermenting this wine. Yeast is one of the key agents responsible for the aromas and tastes of Prosecco, and not just any will do. In Prosecco, yeast carries out two fermentations – the first converts sugars into alcohol, and the second produces carbon dioxide and makes the wine sparkling. The double fermentation produces double the sulfur dioxide levels of regular wines; bringing the levels above 10 mg/l, and preventing it from being labelled “without added sulfites” under current regulations.

The company enologist had to invent a yeast strain that would allow them to avoid this problem. They collaborated with a biotechnology company, performed experimental fermentations, and a yeast strain which produced low levels of SO2 was identified. This particular strain was normally used for fermenting red wines; certainly not white wines or Prosecco.

The second break with tradition was with the taste. Prosecco, the most typical wine of the Veneto region, owes its characteristic sweetness to the high levels of residual sugars, which in the absence of SO2 can attract bacteria or cause the wine to undergo uncontrolled yeast fermentations in the bottle. Once again a non-traditional course was taken, keeping the fermentation going in heated vats until an extremely dry wine was obtained.

Finally, avoiding sulfur dioxide and still obtaining a microbially-stable Prosecco required the use of highly advanced vinifying and bottling machinery. In the absence of sulfur dioxide, the light white wine was especially prone to oxidation. The entire process had to be performed in absence of oxygen, and they substituted it with nitrogen in the vats. Lastly, a new bottling machine was bought, which added protection with a set of micro-filters to prevent a microbial infection, should any air come into contact with the wine. Even in sales, the wine continues to be protected; it is the only Perlage wine to be sold in a cardboard box, with storage instructions spelled out on the side.


4 responses to “Italian Organic Wine and Sulfites – Three Different Approaches”

  1. Richard G Avatar
    Richard G

    The wine yeast Saccharomyces cerevisiae naturally produces up to 40 mg/L (40ppm) sulfur dioxide during fermentation. Yes naturally. So orgainic winemakers should just get over it. I’m more worried about organic producers spraying tons of Copper oxychloride (an ok chemical by many organic certifying bodies). It is a complete nasty and no amount of reassurance that it is “traditional” or nice names like “Bordeaux mix” will change the fact that it is non-organic and non-biodegradable. So the issues surrounding the use of SO2 are completely blown out of proportion.

    But I won’t hold my breath waiting for reason to pervade the organic lobby as science has always taken a back-seat to superstition and self-righteousness.

    In case you’re wondering, I’m all for the principle of organic production, but as a scientist I’m against hypocrisy and illogical thinking.

  2. Brava Anna, beautiful article and beautiful pictures!

  3. Anna, thank you so much. Your article and interviews were so interesting. These winemakers really made their struggles with being organic and the whole S02 issue clear. Thanks again for your efforts. jr

  4. Dear Richard,

    Thank you for your comments; I absolutely agree that the issue of copper spraying is a sore point for organic winemaking, and while inquiries are being made into substances that could substitute copper, the area requires much more research. As far as the ‘illogical thinking’ in the sulphur debate is concerned, let me note that research has been done into how SO2 affects the tastes and smells of wine, so it is not completely inconsequential. However, as I argue in my other article ‘A Case of Ethics’, some organic producers strive to limit SO2 in their wines because they believe this is the right thing to do for their wines and their terroirs. Even the new pan-European wine regulation is unlikely to limit SO2 levels drastically, so the use of SO2 will remain a personal choice of the winemaker. It is this passion for communicating the soil and taste of one’s region that is key for the entire wine sector – wine production has always been closer to poetry and craft than to science, and this lack of scientific rigour is the reason why wine continues to surprise and fascinate us so.

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