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1 ACS Webinars We will start momentarily at 2pm ET Download slides & presentation ONE WEEK after the webinar: Contact ACS Webinars at Have Questions? Use the Questions Box! Or tweet using #acswebinars Download slides & presentation ONE WEEK after the webinar: Contact ACS Webinars at

2 ONE WORD TO DESCRIBE ACS WEBINARS THANK YOU FOR THE SUBMISSIONS! precise excellent TM brilliant enthusiastic entertaining Contact ACS Webinars at Upcoming ACS Webinars Thursday, January 17, 2013 Alternative Careers: From the Lab Bench to the Kitchen Bench Mr. Bill Courtney, Cheese-ology Ms. Iryna King, Rubicon Genomics Thursday, January 24, 2013 Ignorance: Why Science Shouldn t Start with a Hypothesis Dr. Stuart Firestein, Columbia University Dr. Darren Griffin, University of Kent Contact ACS Webinars at acswebinars@acs.org

3 Stay Tuned for your chance to win! Riedel Decanter Oster Wine Chiller & Opener 5 ACS WEBINARS January 10, 2013 A Toast to the Chemistry of Noble Grapes Dr. Susan Ebler UC Davis Dr. Sara Risch Popz Europe Download the presentation ONE WEEK after webinar: Contact ACS Webinars at acswebinars@acs.org

4 A Toast: To the Chemistry Of Noble Grapes Susan E. Ebeler Department of Viticulture and Enology University of California, Davis, CA Winemaking Grape Varieties Vitis vinifera Old World/European grapes Native to Asia Minor, Black and Caspian Sea area Photo:

5 Winemaking Grape Varieties Noble Grapes V. vinifera varieties historically considered to make high quality wine Sauvignon blanc Riesling Chardonnay Pinot noir Cabernet Sauvignon Merlot Photo: Domaine Chandon Chardonnay Winemaking Grape Varieties Numerous cultivars (varieties) of V. vinifera (> 5000?)

6 Winemaking Grape Varieties Different varieties may give a wine varietal character (flavor, aroma, color, etc.) Cabernet Sauvignon Sauvignon Blanc Syrah Winemaking Brief Review

7 GRAPES (white or red) Destem Crush * WHOLE MUST (white or red) Pomace (Skins and Seeds) Press WHITE JUICE RED MUST Add Saccharomyces Ferment WHITE WINE RED WINE Add Saccharomyces Ferment Secondary microbial fermentation * Settle to remove yeast lees Filter * Store/age in oak * Transfer to bottle RED WINE Press & Settle Pomace & Lees (Skins, Seeds, Yeast) FINISHED WHITE WINE Secondary microbial fermentation * Settle to remove yeast lees Filter * Store/age in oak * Transfer to bottle FINISHED RED WINE Winemaking But wines frequently are not 100% of a single variety. Blending

8 Blending Grapes Variety A Grapes Variety B Grapes Variety C Ferment Ferment Ferment Grapes Variety A Grapes Variety B Grapes Variety C Wine Variety A Wine Variety B Wine Variety C Blend Blend Final Wine Crush, Ferment Final Wine A varietal designation on a wine label indicates that the wine contains at least what per cent of the listed grape variety? A. 50% B. 75% C. 90% D. 95% E. 100% Find information at

9 Blending Why blend? Increase flavor complexity Maintain consistent character/quality Develop winery-typical wines But.. Relationships between chemical composition and sensory properties of blends? Changes in composition and sensory quality of base wine vs blend? Wine Blends Characterizing the chemical and sensory profiles of US Cabernet Sauvignon wine and blends Hjelmeland, King et al., 2012, Am. J. Enol. Vitic. doi: /ajev

10 Chemical Analysis Gas chromatography for aroma compounds Chromatogram Hot Inlet Absorbent coating GC Oven Helium Mass Spectrometer N. Lloyd, 2010 Chemical (GC) Analysis 61 compounds Esters (isoamyl acetate) Alcohols (isobutanol) Terpenes (linalool) Volatile acids (acetic acid) Lactones (g-nonalactone) Norisoprenoids (b-damascenone, b-ionone) Carbonyls (hexanal, diacetyl) Etc.

11 Sensory Analysis Sensory Analysis Controlled conditions (light, temperature, serving conditions, etc.) Requires panelist training Human becomes an analytical instrument to provide information about sensory attributes

12 Sensory Analysis Appearance, Aroma, Taste sensory attributes defined and quantified Use multivariate statistics to relate chemical and sensory measurements PC2 x-expl 13%, y-expl 11% Multivariate statistical analysis PLSR2 using UnScrambler Trans-linalool oxide CS4 Benzyl alcohol MIBP CS8 Overall aroma Titratable acidity Eucalyptol g-nonalactone Ethyl isovalerate CS14 Ethyl butyrate Ethyl-2-methylbutyrat Farnesol CS11 CS15 0 CS1 (Z)-3-Hexenol CS17 5-Methylfurfural CS5 CS18 Ethyl hexanoate Ethyl isobutyrate g-dodecalactone CS21 a-terpinene CS7 2-Ethylphenol b-ionone ph Syringol Isoeugenol b-damascenone CS9 CS20 Ethyl octanoate CS24 Ethyl acetate 2-Phenethyl alcohol Hexanol a-ionone Guaiacol CS13 Overall flavor Alcohol Sweet 4-Methylguaiacol Limonene Trans-oak lactone Isobutanol Cis-linalool oxide Camphor Residual sugar Fresh fruit Ethyl decanoate Methionol Eugenol 2-Phenethyl acetate Complexity CS16 Cis-oak lactone Sharp Isoamyl alcohol Vanillin CS19 Acetic acid Octanal Hexyl acetate Furfural CS12 CS23 CS22 Free SO Phenylacetaldehyde 2 Alcohol Linalool Total SO 2 b-citronellol CS2 Isoamyl acetate Hexanal Acetoin Berry CS6 Diacetyl Butterscotch CS3 Vitispirane II CS10 Vitispirane I 4-Ethylphenol 4-Ethylguaiacol a-cedrene Vegetal Barnyard Wood Pepper r-cymene -0.3 PC1 x-expl 25%, y-expl 35%

13 Blending Relationships between chemical composition and sensory properties But.. Wines not differentiated by region, price, age (varietal blend) Changes in composition and sensory quality of base wines vs blends? Chemical and Sensory Changes: Base Wines vs Blends Grapes Variety A Grapes Variety B Grapes Variety C Cabernet Franc Cabernet Sauvignon Merlot Hopfer et al Am. J. Enol. Vitic.63: ; doi: /ajev Ferment Ferment Ferment Wine Variety A Wine Variety B Blend Wine Variety C Final Wine

14 Which of the following grape species are native to North America? A. Vitis labrusca B. Vitis rotundifolia C. Vitis rupestris D. Vitis vinifera E. Vitis amurensis Base Wines vs Blends Base wines had different sensory and chemical properties Chemical composition changed consistently as ratios of base wines in blends changed

15 Can 2 Can % Can 2 Can % Base Wines vs Blends Similar sensory properties possible with different blends Sensory properties did not change consistently attribute intensities were enhanced, suppressed, averaged depending on blending ratio All base wines and the Cab.Sauv. blends Can % % Base Wines vs Blends Perceptual processes in understanding aroma/flavor quality of mixtures are not well understood More work is All base wines and the Cab.Sauv. blends needed Can % %

16 Summary V. vinifera predominates in winemaking Numerous V. vinifera cultivars (varieties) used Blending of varieties is common influences flavor, quality, style Chemical composition and sensory properties influenced by blending But, difficult to predict flavor properties of a blend from composition Studying Viticulture & Enology at UCDavis B.S. in Viticulture and Enology M.S. in Viticulture and Enology PhD in Various Disciplines (Agricultural Chemistry, Food Science, Microbiology, Plant Biology, Horticulture, Genetics, Engineering, etc..) Certificate in Winemaking for Distance Learners making/ University Extension 1- and 2-Day Shortcourses

17 References/Information Sources Principles and Practices of Winemaking, Boulton et al., Chapman & Hall, 1996 (ISBN ) Chemistry of Wine Flavor, Waterhouse & Ebeler, American Chemical Society, 1998 (ISBN ) Authentication of Food and Wine, Ebeler et al., American Chemical Society, 2007 (ISBN ) Polaskova et al., Chemical Society Reviews, 2008, 37: , DOI: /b714455p Ebeler and Thorngate, J. Agric. Food Chem., 2009, 57: , DOI: /jf Journal of Agricultural and Food Chemistry American Journal of Enology and Viticulture greenrmi.ucdavis.edu rmi.ucdavis.edu THANK YOU

18 ACS WEBINARS January 10, 2013 A Toast to the Chemistry of Noble Grapes Dr. Susan Ebler UC Davis Dr. Sara Risch Popz Europe Download the presentation ONE WEEK after webinar: Contact ACS Webinars at acswebinars@acs.org Stay Connected ACS Network (search for group acswebinars) LinkedIn (search group for acswebinars) Contact ACS Webinars at acswebinars@acs.org

19 Upcoming ACS Webinars Thursday, January 17, 2013 Alternative Careers: From the Lab Bench to the Kitchen Bench Mr. Bill Courtney, Cheese-ology Ms. Iryna King, Rubicon Genomics Thursday, January 24, 2013 Ignorance: Why Science Shouldn t Start with a Hypothesis Dr. Stuart Firestein, Columbia University Dr. Darren Griffin, University of Kent Contact ACS Webinars at acswebinars@acs.org And the Winner Is!!! Riedel Decanter 39

20 But wait There is still another chance to win! Simply let us know: Tell us your favorite wine and it s best food pairing? Let us know on facebook.com/acswebinars or by at acswebinars@acs.org Oster Wine Chiller & Opener 40 ACS Webinars ACS Webinars does not endorse any products or services. The views expressed in this presentation are those of the presenter and do not necessarily reflect the views or policies of the American Chemical Society. Contact ACS Webinars at acswebinars@acs.org 41