Before Sulfite-Free Wines: Sulfiting in the Cellar

Sulfur dioxide, potassium bisulfite, and sodium bisulfite are the three substances most commonly used by winemakers and food producers to prevent possible wine oxidation. Their primary purpose is their preservative and stabilizing properties, along with disinfectant and antibacterial effects. These substances, available in liquid, gaseous, or more commonly powdered form, are considered allergens as they can cause various reactions in sensitive individuals. In large amounts, sulfites can also cause unpleasant symptoms in non-sensitive people, including headaches and the recurring .

The Sulfite Addition Process

In the cellar, these substances can be added at various stages:

• On the harvested grapes, to counteract microbial agents before fermentation;
• Throughout fermentation, particularly during racking or the final stages, when the must is rich in microorganisms and more exposed to external agents;
• At bottling, to preserve the wine and prevent spoilage.

The addition of these preservatives and stabilizers can therefore affect the entire production process, from grape harvesting to bottling. These practices apply to all wine categories, from reds and whites to sparkling wines and rosés, not to mention dessert wines and so-called “noble rot wines,” which are particularly exposed to risks.

Regulations on Sulfite Levels

The amount of additives, which must be kept moderate to preserve the wine’s authenticity, is not left solely to the winemaker’s discretion. EU Regulation 203/2012 of March 8, 2012, sets maximum limits to protect consumers’ health, reducing those established by Regulation 606/2009. Maximum allowed levels for common wine types are:

• 100 mg/l for red wines with less than 2 g/l residual sugar;
• 150 mg/l for white and rosé wines with less than 2 g/l residual sugar;
• 155 mg/l for quality sparkling wines;
• 220 mg/l, 270 mg/l, 320 mg/l, or 370 mg/l depending on the type of sweet wine.

These maximum values are set by European regulations. Higher limits are allowed in wines with residual sugar to maintain organoleptic balance and prevent refermentation.

For quality wine production, the common practice is to remain well below these limits, especially for natural and artisanal wines, which often stay below 30–40 mg/l and are therefore considered wines with no added sulfites.

Sulfite-Free Wines: Features and Types

The practice of sulfiting is very old and part of human culture. It is not, as many believe, a modern industrial technique. Even the Ancient Romans used sulfur dioxide, naturally present near volcanoes, to disinfect fermentation vats.

Today, no equally effective alternatives have been found, but under consumer demand, many producers have started to reduce sulfite usage, in some cases producing wines with no added sulfites. This is the case for producers like Movia and Dettori, who avoid all enological additives in their top labels.

To limit or eliminate sulfites without compromising the wine’s preservation, certain requirements and alternative solutions must be observed, keeping in mind that:

• strict vineyard management and careful selection during harvest promote healthy grapes with a moderate microbial load;
• cellar hygiene must be optimal;
• polyphenol content obtained through skin maceration protects against oxidation and spoilage;
• exposure of must and finished wine to oxygen must be limited to prevent oxidation;
• wines produced without added sulfur must be stored under ideal cellar conditions.

It is important to note that a small amount of sulfites naturally forms during fermentation, so minimal levels are almost always present except in rare cases. Since the law requires producers to declare sulfite content above 10 mg/l, many “sulfite-free” wines paradoxically carry this label. Also, when swirling the glass and exposing the wine to oxygen, up to 40% of the sulfur dioxide in the bottle can be released.

Discover sulfite-free wines for sale online and on special offer at Callmewine. Find labels from around the world and across Italy, from Piedmont to Sicily, complete with detailed product sheets.