Wine Can Boost Health, But Vegetarians Beware

(March 10) -- This week, science again raised a glass to wine -- this time for its potential to help women keep off excess weight. But as wine's health benefits keep making headlines, those who choose not to eat animal products should cast a wary eye on the hidden ingredients in their next bottle.

Wine is clarified using a fining process, where sediment, proteins and other particles are filtered out to produce a clear drink with a flavor that's everything from fruity to earthy to multifaceted -- just not rancid or yeasty, two tastes that unwanted extras tend to imbue.

Animal products have been a longtime favorite fining agent among wine manufacturers. They've been used for centuries, they're effective and -- perhaps most important -- the byproducts of animal agriculture are dirt-cheap. Among the most commonly used:

Isinglass: A collagen that's made out of fish bladders and is also used to manufacture some glues.

Gelatin: Derived from the collagen of animal bones, gelatin is also what lends shape to Jell-O desserts.

Casein: A protein found in milk that absorbs suspended materials in wine. It can trigger allergies in some wine drinkers.

Albumen: The cytoplasm of an egg, also known as an egg white. It's also used to filter vinegar and dyes.

Bull's blood: It's illegal in the U.S. and Canada, but wines from the Mediterranean are still sometimes purified using dried blood.

The animal products play a critical role in crafting the final bottled product, but few traces remain once the wine has been purified, packaged and sold.

And if you're not attracted to wine's notorious health benefits, you should still be wary of what's lurking on tap or in your cocktail. Dozens of well-known beers, including Guinness, and liquors -- especially vodka -- are also purified using the same animal ingredients.

Wine and liquor manufacturers aren't required to list their filtering agents on the bottle, so the best way to find out what's been used to purify your pint is by calling the company. Online guides can also be a good place to start.

Animal-free wines are often filtered with clay or carbon. And fortunately, most of wine's health perks have everything to do with a key ingredient -- resveratrol -- and nothing to do with how they're filtered.