Sulfites in Wine: The Myths, the Facts, and the Truth

“Contains Sulfites.” Just two little words — yet so frequently misunderstood! Words you see on almost every bottle of wine. What are sulfites? Are they really bad? Do they cause wine headaches or other related ills?

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The term ‘sulfites’ is an inclusive term for sulfur dioxide (SO2). SO2 is a preservative and widely used in winemaking (and indeed most food industries), because of its antioxidant and antibacterial properties. SO2 plays a very important role in maintaining a wine’s freshness.

Consumption of sulfites is generally harmless, unless you suffer from severe asthma or do not have the particular enzymes necessary to break down sulfites in your body. The amount of sulfites that a wine can contain is highly regulated around the world. Any wine containing more than 10 parts per million (ppm) of sulfur dioxide must affix to the label ‘contains sulfites’.

Myth #1: Red wine has extra sulfites, and therefore causes headaches

In the EU the maximum levels of sulfur dioxide that a wine can contain are 160 ppm for red wine, 210 ppm for white wine and 400 ppm for sweet wines. Quite similar levels apply in the US, Australia and around the world.

The fact that red wines typically contain less sulfites may seem surprising to people who blame sulfites for their red wine headaches!

Red wines contain tannin, which is a stabilizing agent. Additionally, almost all red wines go through malolactic fermentation. Therefore, less sulfur dioxide is needed to protect the wine during winemaking and maturation. So there goes myth #1.

Myth #2: Sulfites in wine cause headaches

Medical research is not definitive on the relationship between sulfites and headaches. There are many other compounds in wine such as histamines and tannins that are more likely connected to the headache effect (not to mention alcohol!).

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Myth #3: Wine should be avoided, because of the sulfites it contains

Another surprising fact is that wine contains about ten times less sulfites than most dried fruits, which can have levels up to 1000 ppm. So if you regularly eat dried fruit and do not have any adverse reaction you are probably not allergic to sulfites.

While the figures I have stated are maximum SO2 levels, discussions with many winemakers over the years would lead me to believe that in practice, sulfite levels are generally well below the maximum permitted limits.

Myth #4: Sulfites are inherently unnatural

Apart from the potential allergic reaction, many people are against sulfites, because they feel they are an unnatural addition when making wine. While that view is valid, it is important to remember that sulfites are also a natural by-product of the yeast metabolism during fermentation. So even if you do not add any additional SO2, your wine will still contain sulfites.

A better understanding of how sulfur dioxide breaks down and binds during winemaking, better winery hygiene, and more careful viticultural practices to ensure healthy grapes (i.e no rot) have all greatly helped to reduce the need for SO2 additions during winemaking. Today, there are many winemakers who refrain from adding any SO2 until after the fermentation is complete.

Why sulfites are necessary

There are really very few wines that are made without some use of SO2. This is because wine is perishable, prone to oxidation and the development of aldehyde off-odors. SO2, particularly for white wines, is important for freshness. Wines without any SO2 generally have a shorter shelf life – about six months, and need to be kept in perfect storage conditions. Given that a winemaker has very little control over the wine’s storage conditions from the time the wine leaves the winery until it is consumed, it is little wonder that SO2 is so widely used to help guarantee that the bottle of wine you open will be fresh and clean, and taste as the winemaker intended.

Additionally, one of the reasons that you see more wines labeled ‘made from organically grown grapes’ than labeled ‘organic wine’ is because in the US organic wine must not have any added SO2.

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Sulfur-Free Wines

All that said, we are beginning to see a number of ‘natural’ wines on the market, where little or no SO2 is added. As indicated earlier, this is easier with red wines, because the tannin acts as a as a natural anti-oxidant. It also helps if natural wines are sold locally.

Some sulfur-free wines to look for include:

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Catherine & Pierre Breton from the Loire. They make one wine without any SO2 addition during winemaking. 2006 Catherine & Pierre Breton Bourgueil Nuits d'Ivresse ( $26), is 100% Cabernet Franc. It is made from organically grown grapes, unsulfured and unfiltered. The label clearly states that the wine "doit être stocké en dessous de 14ºC", - a warning that the wine should be stored at below 14 degrees C (57 degrees F). Note: There is a tiny amount added before the bottling to keep the wine stable in shipping, but it is so minimal as to be undetectable in testing.

Pierre Frick from Alsace makes a range of wines ‘sans souffre’. The 2007 Riesling and Pinot Noir wines ‘sans souffre’, are available at Chambers Street Wines in NYC (at about $22 to $24).

Frey Vineyards, Mendocino – one of the first organic and biodynamic wineries in California. Their range include wines made without the addition of any sulfur dioxide. Organic Natural Red, NV from Mendocino is a blend of Carignan, Zinfandel and Syrah and costs only $8. Their unsulfured white Organic Natural White also, $8, is a blend of Chenin Blanc and Chardonnay.

Domaine des Deux Ânes, in the Languedoc, is another organic wine producer using very little sulfites. I mentioned one of their wines in last week's post on the wines from the Languedoc Roussillon. Great value, delicious wines and widely available.

What is your view on sulfites in wine?

Mary Gorman-McAdams, DWS, is a New York based wine educator, freelance writer and consultant. She hold the Diploma in Wine & Spirits from the Wine and Spirits Education Trust (WSET), and is a candidate in the Master of Wine Program.

(Image: Faith Durand; wine producers)