Sleuthing Out What's In Wine (Part three of four)
|A magnified view of tartrate crystals, also known as tartartic acid.|
|Photo courtesy of Fresno State University|
Like all food products, wine can be made without preservatives. But while the idea is appealing, the reality is a problem for a product that people routinely store for a decade or more before consuming.
Without sulfites -- the most common wine preservative -- many wines would spoil before ever reaching your local wine shop.
Sulfites are a naturally occurring part of the fermentation process, and winemakers have used sulfur dioxide as a preservative in one form or another for hundreds of years.
Today, a compound like potassium metabisulphite is added in tiny amounts at more than one stage during the fermentation process, and it releases sulfur dioxide that inhibits the growth of mold, vinegar-causing bacteria and other unwanted micro-organisms. It also prevents the wine from oxidizing.
I often hear people implicate sulfites as the cause of a physical ailment they may have. I never heard those complaints until 1987, when the government began mandating that the phrase "Contains Sulfites" be attached to any product that contained more than 10 parts per million of sulfites. Dried fruit also contains sulfites, in more massive doses than in wine, but no one ever complains about ailments from dried pears.
Red Wine Headache (RWH) is an actual syndrome, but studies have shown that the cause isn't sulfites. More likely it's histamines, naturally occurring compounds found in animals and plants.
"In wine, the amounts of histamine and tyramine are generally pretty small, and by themselves wouldn't cause any problems, but you have this alcohol, which inhibits the body's defense system," says Mark Daeschel of the Department of Food Science and Technology at Oregon State University. "Ethanol acts as an MAO inhibitor."
He said people who take MAO inhibitors (a class of antidepressants) are warned not to ingest foods that have histamines, and that should include red wine.
Some asthmatics have reactions triggered by sulfites, although a researcher in the field says wine doesn't contain enough to be dangerous to most.
"The research I have seen has shown that reactions to sulfites are dose-related, and I have failed to find a reaction below 250 parts per million," said Dr. Keith Marton, chief medical officer of Legacy Health System and clinical professor of medicine at Oregon Health and Sciences University in Portland. The legal limit for U.S. wines is 350 parts per million; UC Davis studies show California wines average 80 ppm.
Marton adds: "There is at least one well-designed study that showed that red wine drinkers had less asthma than non-wine drinkers.
Still, asthmatics and others worried about sulfite can find wines with none added, although don't be misled by the lack of a warning label on European wines. Andrew Waterhouse, head of the Department of Viticulture and Enology at UC Davis, says: "Europeans are using the same amount of sulfites we are. They just don't have the labeling requirements we do."
Frey Vineyards in Redwood Valley just got a gold medal at the Mendocino County Fair wine competition for its 2003 Frey Vineyards Organic Mendocino Syrah, made with no sulfites added. Winemaker Jonathan Frey admitted that his winery has had "our ups and downs (making organic wine) over the years."
"With modern winemaking equipment, I think it's possible to make a sulfite-free wine," Frey says. "If you have healthy fruit and get a clean fermentation, the wine is stable."
"To me, making wine without sulfites is like climbing Mt. Everest without an oxygen mask," said Vinovation's Smith. "People will say you're crazy, but you might be able to do it."
Frey says, "We aren't making wines for long-term storage. We recommend that people drink our reds within five years of the harvest."
And if there are any floaties in it, or in any of your wines at home, relax. Wine is one liquid that can handle the occasional solid.
|Dan Berger is a freelance wine writer in Sonoma County.
Originally Published on ©2004