The Truth about Tannins

Wine21.com >WineNews >와인 스토리     와인 스토리              제목 | THE TRUTH ABOUT TANNINS      작성자 | wineshop   등록일 | 2001-05-10     Some red wine producers are turning to chemical companies for tannins By Daniel Sogg - wine spectator Great wines must be balanced--an integration of concentrated flavors of ripe fruit with firm structure and backbone. In red wines, the backbone mostly comes from tannins, which are a natural component of the skins, seeds and stems of grapes. Making red wine is, in large part, an effort to manage the quantity and quality of tannins that are extracted during and after fermentation. (A different kind of tannin can also be extracted from oak barrels, which are often used to mature red wine). Sometimes, however, producers find that they can|t extract enough tannin, or the right kinds of tannin, from their grapes and barrels. And though most winemakers don|t make a point of advertising the fact, for years they|ve added powdered tannin preparations before, during and after fermentation in order to achieve the balance they desire.  Reasons for adding tannins depend upon wine region, vintage conditions and winemaking philosophy. Winemaker Jacques Lardiere of Maison Louis Jadot in Beaune, France, says some estates in Burgundy have been adding tannins for years. "In a difficult vintage, when tannins are a bit deficient, you might need to add them," he says. Tannins play a crucial role in protecting a red wine|s flavor and aromatic components from the ravages of oxygen. As tannin molecules oxidize, they bond together, or polymerize, to form longer chains, which have a less astringent mouthfeel. As long as there|s a sufficient supply of tannins, polymerization occurs naturally as a wine ages. Lardiere says that additional wood tannin acts as a sort of fall guy by absorbing oxygen that would otherwise consume the grapes| natural tannins. Those grape tannins can then gradually polymerize, contributing to the mellowness associated with maturity. Lardiere adds tannins to his lighter wines, like Marsannay and Santenay. "There|s nothing astonishing or troubling about this," he says. "Tannin isn|t used to hide anything, but to reveal the quality of tannins that exist naturally in wine grapes." Nor is Lardiere the only winemaker at a famous Burgundy estate who admits to adding tannins. Andre Porcheret, former winemaker at the renowned Hospices de Beaune and Domaine Leroy, has known of the practice since he started working in Burgundy in 1955. He adds tannins to fix color and to provide grip. It might be old hat in France, but it|s a recent arrival in California, where many producers are experimenting. Scott Laboratories, in Petaluma, Calif., is one of the leading domestic distributors of fermentation products. "We sell [tannins] to hundreds and hundreds of wineries," says Steve Doherty, inside sales manager for Scott. "We have customers all over California, the Midwest, Texas and New York." Scott Laboratories| most popular additive is called VR Supra, a blend of tannins extracted from exotic wood and grapes. One kilogram (2.2 pounds) of VR Supra sells for $25. Other additives can cost up to $261 per kilogram. Winemakers add as much as three pounds of tannin, preferably in small increments, for every 1,000 gallons of wine. "You have to do it by taste, and you can|t do it by the numbers," says Diana Burnett, fermentation products sector manager at Scott. Despite the growing popularity of tannin additives in California, many producers refuse to go on record, fearing that consumers would stigmatize the practice as "unnatural" and "interventionist." "What people say they do and what they do are sometimes two different things," says Craig Williams, winemaker at Joseph Phelps Vineyards in St. Helena, Calif. "Not that everyone|s lying, but sometimes people are more comfortable speaking in generalities." Williams has tried tannin additions in Syrah, but does not currently use the technique for any commercial wines. Many of the virtues attributed to tannin addition are based on anecdotal experience rather than on hard science. But there is some solid chemistry backing the idea, according to Andrew Waterhouse, professor of enology at the University of California, Davis, the state|s leading wine research institution. The notion that additives help preserve wine makes sense, says Waterhouse. "The structure of wine will fall apart when the tannin [supply] is totally exhausted [through oxidation], so you need to preserve the wine long enough to develop bottle bouquet." But there|s no consensus about tannin|s role in fixing color. Waterhouse and some winemakers are convinced that tannin additions enhance a chemical process known as the "co-pigmentation effect," which adds depth and hue to the color of young red wines. Nonetheless, as red wines age, youthful color components deteriorate, and there|s no evidence that maximizing the co-pigmentation effect leads to darker colors in maturity. Michel Rolland, one of the world|s most respected consulting winemakers--with clients in nearly a dozen countries, including France, California, Greece and Argentina--hasn|t seen the point of tannin additives. He has little regard for wines that need additions to preserve color, for example. "Tannins can fix the color, but it fixes it for people who|ve badly prepared their vineyard and who aren|t making great wines," he says. "Whenever a new tannin product comes out, they bring it to me. I|ve never been convinced. In my opinion, it makes for wines that are a bit rigid and austere." The gradual oxidation and polymerization that occurs in barrel is quite different than the effect that comes from adding powdered tannins, says Rolland. However, he won|t categorically dismiss the practice. "Australia has conditions very different than what I know," he says. "And I don|t make Pinot Noir. But in Bordeaux, I know tannin addition is a heresy. One doesn|t make great wines in Bordeaux adding tannin." Nonetheless, tannins are added in Bordeaux--if only to lesser wines, according to Yves Glories, director of the enological faculty at Bordeaux|s Institut d|Oenologie. He says that additives are used primarily to stabilize color and also to inhibit the enzymatic activity of botrytis. But in Australia, powdered tannins are added to some of the country|s best wines. John Duval, chief winemaker at Penfolds, adds it after fermentation to the legendary Grange Hermitage. "It stabilizes the structure," he explains, noting that tannin additions were a basic tenet of the winemaking philosophy of Max Schubert, first winemaker of the Grange. But even in Australia, there|s no consensus among winemakers. "There are very different views of what you do by adding tannins," says Peter Godden, winemaker and manager of industry service at the Australian Wine Research Institute in Adelaide. "Some say it|s only for unimportant wines, others will use it for big, structured wines." One point of agreement is that tannin is a major part of the structure that delineates mouthfeel in red wines. Wines convey a tactile impression, a sense of weight and texture. Tannins are analogous to the beams and girders supporting a house. Without that structure, the edifice of fruit collapses. But wineries need to exercise restraint. Just as brawny muscles wouldn|t flatter a ballerina, wines of polish and elegance are probably not ideal candidates for substantial additions. When overdone, tannins can dramatically alter the style of a wine. Adding any tannins at all raises a philosophical question, one that applies equally to the more common practices of adding sugar (chaptalization) or acidity to a wine. In essence, it is a debate between purity and quality. Purists argue that "great wine is made in the vineyard," not concocted in the laboratory. Interventionists maintain that skillful winemakers should correct any natural deficiencies in the grapes, in order to maximize wine quality. In practice, of course, the two sides often agree, but when new techniques arise, so do the old disputes. Despite unanswered questions and risks of excess, some winemakers will continue to experiment, trying to improve on nature|s handiwork. "I|ve found a lot of effects for different wines. Some were good, some were negative," says Godden. "You can do damage by adding too much. Winemakers need to experiment to learn, to feel comfortable with what a particular addition will do to a wine."