HYBRID CULTIVARS PG 3 NEW PRODS YEAST PGS 4-31 PGS 32-41 FERM MGMT Photos courtesy of University of Minnesota TANNINS Gris Frontenac PGS 42-49

Article TANNIN AND HYBRID VARIETIES HYBRIDS In the Midwest and Northeast, nia, where the anthocyanins may be Iowa. For tannins added at the fer- PGS 50-53 cold-hardy hybrid varieties are the around 200 ppm and the tannins are menter, they compared the St. Croix dominant winegrape cultivars grown. well over 1000 ppm. At the University control against additions of 400, 800 The combination of climatic condi- of Illinois, Bradley Beam has been do- and 1200 ppm (10 lb/1000 gal). At tions and the inherent properties ing similar testing with Frontenac and the workshop in December 2008, PGS 54-61 of many of the red cultivars result , while Dr. Joseph Fiola the 1200 ppm addition was preferred ML BACT in that are very low in tannin, of the University of Maryland has by the majority of attending - often lacking mid-palate intensity and been doing trials on Chambourcin. makers. They also took the same St. having a short finish. Tannins, besides Using the Adams-Harbertson Assay Croix (untreated) and did additions giving the familiar puckery, astringent for tannin, Beam found the tannin of finishing tannins at levels ranging PGS 62-65

character, also contribute to body, levels for Frontenac to be from 50 from 100-600 ppm. Four different EQUIP & LAB mouthfeel and complexity. They are to 200 ppm. One generally needs at tannins were trialed. There was a powerful anti-oxidants and play a least four times the tannins to antho- 100% grape tannin, an untoasted oak major role in stabilizing color. cyanins to fully stabilize wine color. tannin, a toasted oak tannin and a

blend of oak and grape tannins. Only PGS 66-71

For several years, Murli Dharmadhi- In 2008, an Illinois winery did a trial MICRO CTLS the untoasted oak tannin seemed to kari and Sebastian Donner of Iowa with Frontenac, comparing different have no sensory impact at the levels State University have been experi- levels of enological tannin additions added. All of the others were pre- menting with the use of enological at the fermenter. One-third had no ferred by the attending winemakers tannins on red hybrid varieties (pri- addition, one-third was treated with 8 PGS 72-77 in the 400-600 ppm range. ENZYMES marily St. Croix and Frontenac). lb/1000 gal, and one third was treated with 16 lb/1000 gal. In subsequent Further testing of the wines will be At Iowa State, untreated St. Croix tastings over the following year, necessary to determine the longev- wines were tested and found to have two-thirds of the surveyed winemak- ity of the flavor and body impacts, tannin levels between 150 and 200

ers preferred the heaviest treatment. and to see if the tannin addition PGS 78-79 ppm. The same wine had anthocyanin SPECIALTY Virtually no one preferred the control. helped the overall aging potential of levels between 2100 and 2400 ppm. the wines. This is in sharp contrast to typical The same year, Dharmadhikari and vinifera numbers from Califor- Donner held a tannin workshop in FINING

Bradley Beam, Enology Specialist, Department of Food Science, Dr. Sebastian Donner, Wine Laboratory Supervisor, PGS 80-87 University of Illinois, [email protected] Enology & Program, Iowa State University, www.extension.iastate.edu/wine Dr. Murli Dharmadhikari, Director and Extension Enologist, Enology & Viticulture Program, Iowa State University, Dr. Joseph Fiola, Viticulture and Small Fruit Specialist, www.extension.iastate.edu/wine University of Maryland [email protected], www.grapesandfruit.umd.edu TOOLS PGS 88-89

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