Just as an FYI, a quote from an organic wine site which I found interesting:
The public often equates organic wines with "sulfite-free" wines. This is inaccurate. Let us apologize for the confusion and try to clear it up for you.
AN ORGANIC WINE IS FIRST AND FOREMOST A WINE MADE OUT OF GRAPES THAT WERE GROWN ORGANICALLY.
Organic wines are produced using organically grown grapes. No pesticides, herbicides, fungicides, chemical fertilizers, or synthetic chemicals of any kind are allowed on the vines or in the soil. Strict rules govern the winemaking process and storage conditions of all imported and domestic wines that acquire certification. Moreover, organic winemakers often avoid many of the chemical substances used to stabilize conventional wines.
THERE IS NO SUCH THING AS A SULFITE-FREE WINE.
Totally sulfite-free wines are an accident of nature; but wines low in sulfites or free of added sulfites do exist. Let us explain. Sulfites are a natural byproduct of the fermentation process. Fermenting yeasts present on all grape skins generate naturally occurring sulfites in amounts ranging from 6 to 40 parts per million (ppm.).
According to Professor Roger Boulton, Ph.D., University of California at Davis, Department of Viticulture and Enology, even if no sulfur dioxide is added to wine, fermenting yeasts will produce SO2 from the naturally occurring inorganic sulfates in all grape juices. Thus, says Boulton, it is impossible for any wine to be completely free of sulfur dioxide.
WHAT ABOUT ADDED SULFITES?
Although technical advances permit the industry to add much less sulfur, most serious winemakers and enology professors concur that to make a consistently stable wine, some sulfites must be added to those naturally present. A handful of winemakers go beyond that; they use no added sulfites at all. However, sulfite agents, when properly handled, are not intrinsically toxic to humans or to the environment, and many feel they are essential in order to prevent oxidation or bacterial spoilage. Therefore, American and European organic winemaking standards allow for the addition of strictly regulated amounts of SO2.
In the U.S., wines can contain up to 350ppm of sulfites. Organic winemaking standards, as adopted recently (12/2000) by the USDA, limit the use of sulfites to 100ppm in all finished products. However, most organic wines contain less than 40ppm of sulfites.
SULFITES IN ORGANIC WINE COMPANY WINES
Our line of wines is regularly analyzed by the local BATF laboratory. On average the reds have about 40ppm of total sulfites (20 to 60) while the whites, along with the sparkling, show up around 70 ppm (50 to 90). Some show none at all (Cartagene or certain vintages of Guy Chaumont wines). This does not represent a criterion by itself for us. We know that all our producers are striving to use the smallest possible amount of sulfites given their respective situation.
WHY DO WINEMAKERS ADD SULFITES TO WINE?
Sulfur has been used as a preservative in winemaking for quite some time. To prevent wine spoilage, European winemakers pioneered the use of sulfur dioxide (SO2) two hundred years ago. Unfortunately, freshly pressed grape juice has a tendency to spoil due to contamination from bacteria and wild yeasts present on the grape skins. Not only does sulfur dioxide inhibit the growth of molds and bacteria, but it also stops oxidation (browning) and preserves the wine's natural flavor.
SULFITES IN OTHER PRODUCTS.
According to Mitchell Zeller of the Washington, D.C. based Center for Science in the Public Interest, sulfites exist in a wide variety of products at levels that are comparable to, or in excess of the concentration that is found in wine. The presence of sulfites ranging from 6 to 6000 ppm is found in products such as fruit juices, dried fruits, fruit concentrates, syrups, sugar, jams, gelatins, cake toppings, baked goods, pizza dough, frozen and dehydrated potatoes, processed vegetables, cheeses, as well as in many prescription drugs.
In the United States, the Bureau of Alcohol, Tobacco and Firearms (BATF) in conjunction with the Food and Drug Administration (FDA) regulates and limits the use of sulfites in wine and has done so for many decades. On January 1, 1987, a Federal regulation was passed requiring that as of January 1, 1988, all imported and domestic wines, beers and spirits exceeding 10 parts per million of sulfites bear the mention "Contains Sulfites" on their label. Wines that contain less than 10 ppm sulfites are not required to put "Contains Sulfites" on their labels; however, this does not mean the wine is "sulfite-free" or contains no sulfites. As established earlier, all wines naturally contain some sulfites.
WHO IS AT RISK?
The FDA says only about .4% of the population, or about a million people, is considered highly allergic to sulfites. According to Dr. Vincent Marinkovich, an allergist and clinical immunologist who has performed extensive research on SO 2, sulfites pose no danger to about 99.75% of the population; the highest risk group are asthmatics (about 5% of the population) and only about 5% of this group is allergic to sulfites.
Many people, however, have little tolerance for sulfites. They are considered sulfite-sensitive. Even for moderate wine drinkers, the average level of sulfites found in many commercial wines can cause heartburns or other side effects. Unpleasant reactions include burning sensations, hives, cramps, and flushing of the skin. For them, organic wines are an especially good choice since they contain minimal amounts of sulfites that will in most cases lie below their threshold level. http://www.ecowine.com/sulfites.htm