Monday, February 13, 2006

Sulfites & Wine

Grape skins not only host the yeast that ferments grapes into wine, they also contain vinegar bacteria that can spoil new wine. Adding sulfites (sulfur dioxide and its salts) helps to prevent the spoilage. Sulfites inhibit the growth of molds and bacteria, curtail oxidation (browning), and also preserve flavor.

According to the Food and Drug Administration (FDA), one percent of the general population and five percent of asthmatics are affected by sulfites. Sulfite allergy symptoms range from mild gastrointestinal distress to death. If you were allergic to sulfites, you would know it. You would be sensitive to many conventional supermarket and convenience foods that are preserved with sulfites.

Getting a headache after drinking wine is usually the result of three factors: sulfites, amines, or overindulgence. We all know when we’ve had too many, but the cause of a throbbing head after one glass of wine has been the subject of numerous studies.

Many people incorrectly blame sulfites for their wine headaches. If your headaches are severe only when you drink red wine, you can rule out sulfites as the culprit. Many highly-processed foods have had sulfites added to them. And, contrary to popular opinion, white wines contain even more than reds!

The third suspect is a group of chemicals called amines, which occur naturally in fermented foods and beverages. Wine contains two kinds: histamines and tyramines. A study conducted by Mark Daeschel, Professor of Food Science and Technology at Oregon State University, confirmed that histamines dilate blood vessels in the brain, while tyramines constrict them. Either effect may cause headaches in people sensitive to one or both of the chemicals. In this case, red wines do generally have a higher content than white wines, but as with sulfites, few people suffer from sensitivity to amines.

A Few Facts

All wines contain sulfites naturally. They are a by-product of fermentation.

There is no such thing as wines that contain no sulfites, or sulfite-free wines.

There are wines that can be labeled as "No Sulfites Added," but these wines still contain between 6 and 15 ppm (parts per million).

There are less sulfites used in wine production today than at any other time in history. Better technology, equipment, and sanitation practices all contribute to less bacterial spoilage, and therefore less need for adding sulfites.

Wines labeled "Organic" do not contain added sulfites, those labeled "Made from Organically Grown Grapes" may contain added sulfites.

To this day, there has yet to be found a better way to keep wine from spoiling than the use of sulfite.

1 Comments:

Blogger Debbie said...

Thanks for this information. Sulfites get a bum rap though they're rarely to blame for that wine headache (I'm betting your "overindulgence" factor causes far more trouble!)

I have known people to ask for sulfite-free wines, not realizing that those are basically flukes since the sulfites occur naturally. Organic wineries won't add sulfites, but it's unlikely that their wines would be sulfite-free.

5:01 PM  

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