Ever wonder what goes into a bottle of wine? The story winemakers love to tell on the bottle label is one of a mystical alchemy of climate, soils, ancient practices and long traditions. Wine labels tend to focus on romance; the small amount of government-mandated information includes the percentage of alcohol, a warning against consuming wine when pregnant or driving, and a disclosure of sulfites.

It might be disenchanting if the label also listed the chicken, fish, milk and wheat products that are often used to process wine. And it would be hard to maintain the notion that wine is an ethereal elixir if, before uncorking, consumers read that their Pinot Noir or Syrah contained Mega Purple (a brand of concentrated wine color), oak chips or such additives as oak gall nuts, grape juice concentrate, tartaric acid, citric acid, dissolved oxygen, copper and water. The mention of bentonite, ammonium phosphate and the wide variety of active enzymes used to make some wines would end the romance.

Wine rules: In a March 28 article on proposed changes in wine labeling regulations, the name of a grape variety was misspelled as Rudy Red. The correct spelling is Rubired.

Federal regulators are considering revamping the rules governing wine labels, and if changes are made, the information revealed may surprise many wine buyers. Additives that supplement what nature failed to provide in an individual wine -- tricks of the trade that winemakers rarely talk about -- could soon be listed in detail on the labels.

The wine industry, through the Wine Institute, the industry's chief lobbying arm, is opposing the regulatory changes. But could new regulations be good news for consumers?

Wine industry consultants familiar with the subject are divided on the question.

Supporters, such as Leo McCloskey, president of Enologix, a Sonoma, Calif.-based wine consulting company that has analyzed the chemical composition of 70,000 wines, say the best wines don't rely on additives. If ingredients were listed on wine labels, the finer wines would stand out.

"The wine industry is completely unregulated," he says. "It would be so useful to have labels that detail everything in a wine. It would tell the consumer what they are drinking."

But critics of the federal initiatives say ingredients labels would make widely accepted winery practices unnecessarily controversial.

"Why freak out the ignorant when we are adjusting something that is already there in the wine?" says Clark Smith, chairman of Vinovation Inc., a Sebastopol, Calif.-based wine industry "fix-it shop."

Smith uses additives of all kinds to turn unsuccessful batches of wine from his 1,200 winery clients into salable products. On the labels of the wines he makes, under his own Wine Smith label, he discloses whether he has used wood chips for mellowing or if he's brought down alcohol content using a controversial process known as reverse osmosis.

But, Smith says, most of his clients don't share his attitude of openness, and he sees no harm in keeping consumers in the dark.

Links to additives

WIDELY accepted processing practices account for some of the additives in wine. Fining -- the practice of using animal proteins such as egg whites to remove impurities -- can result in some of those proteins remaining in the wine. The aging of wine in oak barrels adds not only oak tannins but also can leave traces of wheat paste used to make the barrels.

Animal proteins (chicken, fish, milk) and wheat are examples of allergens potentially present in wine that would be listed under new requirements now being finalized by federal regulators.

Questions remain about how to detect these allergens and how much of a particular allergen needs to be present to warrant listing it on the label. The rules for wine, however, are all but certain to be enacted in the next few months to satisfy allergen labeling rules for all foods and beverages mandated by Congress in 2004.

There is a separate federal initiative on a slower track to list all of the ingredients in a wine as well as the calorie, fat and carbohydrate counts. Proposed ingredient and nutrient rules are expected to be released later this year for public comment.

Because nearly all processed foods and beverages are required to disclose ingredients and their nutritional values, why aren't they already listed on wine labels?