Issue link: http://winesandvines.uberflip.com/i/62507
Inquiring Winemaker TIM P A T TERSON Seed Tannin: A Necessary Evil? G rape seed tannins get no respect. The way some wine- makers talk about them, you'd think they were just another form of MOG, only tucked inside the grapes and impervious to any sorting table. Maybe Thompson Seedless—a vinifera grape, after all—should get another look. We don't need those low-life seeds to propagate vines anyway, so can't we just get rid of them altogether? Alas, a grape seed-free world would be a sad one indeed, and seed tannin-free red wines would be mere shadows of the real thing. The poor little pips get blamed for a host of things they don't cause, and bring some very useful things to the table—enough so that some of the winemakers most intent on removing seeds end up putting seed tannin back into their wines in the form of powdered additives. Let's give some credit where credit is due. Seeds and skins There are several well-known structural differences between seed tannins and skin tannins in grapes, a grab bag of advantages, dis- advantages and features no one is quite sure how to evaluate. Skin tannins include one monomer not found in seed tannin: epigallocatechin. Epigallocatechins are distinguished by having three hydroxyl groups hanging off them—in contrast to the two hydroxyls on the other basic monomeric tannin building blocks, catechin and epicathchin. Does this make any difference once we get to wine? Stay tuned. As Jim Harbertson of Washington State University loves to remind people, seed tannin chains are quite a bit shorter than skin tannin polymers; the ratio is about one to three—10 units on average for seed tannin to around 30 for skin. Therefore, according to the best You know how good your Zinfandel is... Promote your wines to leading Zinfandel enthusiasts and extend your winery's relationship in the market. Join Us! We are champions of Zinfandel— America's Heritage Wine Become part of our proud legacy zinfandel.org • 530-274-4900 Zinfandel Advocates & Producers is a 501(c)(3) non-profit organization. ZAP is dedicated to advancing public knowledge of and appreciation for American Zinfandel and its unique place in our culture and history. 56 Wines & Vines OCTOBeR 2011