The Australian Wine A W R I Research Institute Technical Review No193 August 2011 Registered by Australia Post PP 531629/00034 Table of contents In this issue 1 AWRI notes 6 AWRI Managing Director moves on 6 Technical notes 7 ‘Tropical’ thiol precursor levels in Sauvignon Blanc grapes: the effect of ripening and post-harvest transport 7 Botrytis and disease pressures from vintage 2011 11 Why should we be interested in alternative varieties? 19 Current literature 23 AWRI extension and roadshow calendar 67 Editor: Michael Major, Michael Major Media All enquiries: Rae Blair; email [email protected] Copyright: Reprints and quotations of articles published herein are permitted on condition that full credit is given to both The Australian Wine Research Institute Technical Review and the author/s, and that the date of publication and issue number are stated. ISSN 0816-0805 Cnr Hartley and Paratoo Rd PO Box 197 T +61 8 8313 6600 Published by The Australian Urrbrae Glen Osmond F +61 8 8313 6601 Wine Research Institute South Australia 5064 South Australia 5064 [email protected] ABN 83 007 558 296 Australia Australia www.awri.com.au In this issue AWRI NOTES AWRI Managing Director moves on Dr Sakkie Pretorius, the Managing Director of The Australian Wine Research Institute, is leaving his position to take up a new appointment as Deputy Vice Chancellor and Vice President: Research and Innovation at the University of South Australia. TECHNICAL NOTES ‘Tropical’ thiol precursor levels in Sauvignon Blanc grapes: the effect of ripening and post-harvest transport Grape ripening and post-harvest transport both influence 3-MH precursor levels and the generation of this tropical thiol during winemaking. In grape ripening, low levels of precursors were detected in berries until commercial harvest, where there was a dramatic increase in the last week or so of ripening. Once picked, the way grapes are handled before fermentation can also have a major effect on precursor levels. The length of time between harvest and pressing is an additional variable we are investigating again on a commercial- scale in this current vintage. Botrytis and disease pressures from vintage 2011 Viticulture experiences with Botrytis cinerea this year were heightened by other fungal infections in the pre-season, coupled with a shortage of vineyard chemicals and difficulties in estimating infection levels in vineyards. Winemakers experienced problems with effective laccase detection in juice and wine and appropriate treatment options including pasteurisation. Binding of sulfur dioxide, difficulties with clarification and filtration due to Botrytis-derived glucans, and deacidification of some wines were also required this year. Why should we be interested in alternative varieties? In recent times there has been increased interest in alternative varieties. Is this a passing fad or are there valid reasons for this interest? This article attempts to explain why this interest is quite justified. For example, alternative varieties may be better adapted to future climatic conditions than current mainstream varieties. August 2011 Technical Review No. 193 1 CURRENT LITERATURE Oenology General (page 23) Towards better use of white wine phenolics Pinot Gris/Grigio international standard Technology traces path from vine to wine Antioxidant action of glutathione and the ascorbic acid/glutathione pair in a model white wine Juice and wine handling (page 25) Courte mise au point sur les gommes de cellulose (CMC) aprés une année d’utilisation Nouveaux outils pour lutter contre le goût de réduit The Pinot principles Le décanteur centrifuge Alfa-Laval Microbiology (page 26) Population dynamics of Saccharomyces cerevisiae during spontaneous fermentation at a British Columbia winery Influence of microbiological biodiversity and population dynamics of yeasts on wine quality – an overview Biodiversity of fungal microflora in wine-cellars Analysis and composition (page 27) Influence of yeast strain, canopy management, and site on the volatile composition and sensory attributes of Cabernet Sauvignon wines from Western Australia Stability, antioxidant activity and phenolic composition of commercial and reverse osmosis obtained dealcoholised wines Aroma changes due to second fermentation and glycosylated precursors in Chardonnay and Riesling sparkling wines Associations between the sensory attributes and volatile composition of Cabernet Sauvignon wines and the volatile composition of the grapes used for their production Identification of impact odorants contributing to fresh mushroom off-flavor in wines: incidence of their reactivity with nitrogen compounds on the decrease of the olfactory defect Influence of wine pH on changes in color and polyphenol composition induced by micro- oxygenation Authentication of Italian red wines on the basis of the polyphenols and biogenic amines Electronic nose analysis of Cabernet Sauvignon (Vitis vinifera L.) grape and wine volatile differences during cold soak and postfermentation Iron(III) tartrate as a potential precursor of light-induced oxidative degradation of white wine: studies in a model wine system Analytical and sensorial characterization of the aroma of wines produced with sour rotten grapes using GC-O and GC-MS: identification of key aroma compounds Marketing and packaging (page 32) Food and wine production practices: an analysis of consumer views The drivers of wine regionality ‘Green’ wine packaging: targeting environmental consumers How does Australia rank in the various quality segments of the world’s wine markets? Do consumers value sustainable wine claims? An international comparison Environment (page 34) Reducing CO2, the real pollutant Review: winery wastewater quality and treatment options in Australia 2 Technical Review No. 193 August 2011 Sensory (page 35) Finding the right sweet spot U.S. drinks most wine Wine consumption habits and consumer preferences between wines aged in barrels or with chips Viticulture General (page 36) Tuning your vineyard for the next vintage Spectral discrimination of grape varieties and a search for terroir effects using remote sensing Ce qu’il faut savoir pour réussir le surgreffage Biodynamic and organic – not the only games in town Suivre la biodiversité dans le vignoble champenois Increasing vineyard profits and sustainability The potential for growth of the Tasmanian wine sector Downside of green In search of uniformity: why grape quality varies Defining sustainable viticulture from the practitioner perspective Mothball mistake? Physiology and biotechnology (page 39) Aerial root formation on winegrape cultivars after spring 2007 freeze events Influence of bunch position in the canopy on berry epicuticular wax during ripening and on weight loss during postharvest dehydration Carbohydrate reserves to help predict yields A simple microplate assay to quantify nonstructural carbohydrates of grapevine tissues Pollination dynamics in Vitis vinifera L. Influence of shriveling on berry composition and antioxidant activity of Cabernet Sauvignon grapes from Shanxi vineyards Carbohydrate metabolism in grape cultivars that differ in sucrose accumulation Climate and soils (page 42) Studying water and soil effects Vineyard management systems (page 43) Mechanized canopy management Effects of mechanical pre-bloom defoliation on cordon de Royat pruned Sangiovese (Vitis vinifera L.) vines Managing a severe frost event Integrating canopy management with mechanization Electric pruners have growers talking Grapegrower interview: Hank Ashby Pests and diseases (page 44) Association of Botryosphaeriaceae grapevine trunk disease fungi with the reproductive structures of Vitis vinifera Powdery mildew severity as a function of canopy density: associated impacts on sunlight penetration and spray coverage Crop cultural and chemical methods to control grey mould on grapes Stem injection of triazoles for the protection of Vitis vinifera L. (‘Riesling’) against powdery mildew (Uncinula necator) Resistance of rootstocks depends on the vineyard populations of root-knot nematode New fungicides fight mildew Effect of temperature on Botrytis cinerea, Colletotrichum acutatum and Greeneria uvicola mixed fungal infection of Vitis vinifera grape berries Sunlight enhances fungal disease control August 2011 Technical Review No. 193 3 Inoculum detection to manage grape powdery mildew Irroratrici a recupero prodotto ammortamento e convenienza Le suivi biologique du mildiou Vine improvement and varieties (page 48) Barbera and Nebbiolo, selection continues Developments in Italy’s ampelographic registry Investigations on the identity of ‘Canaiolo bianco’ and other white grape varieties of central Italy Un vivaismo più integrato nella filiera Busy year ahead for Tasmanian Pinot researchers Grapevine European challenge: towards a comprehensive list Home-grown wine grape varieties go back a long way in Asia Gruner Veltliner finds a new home in the Adelaide Hills Exploration and evaluation of grapevine biodiversity using molecular markers Conservation, evaluation and revitalization of native grapevine varieties in Croatia Water and nutrition (page 51) Effects of irrigation and crop load on leaf gas exchange and fruit composition in red winegrapes grown on a loamy sand Wine and health Epidemiology (page 52) Substance use and exercise participation among young adults: parallel trajectories in a national cohort-sequential study Alcohol consumption decreases with the development of disease Commentary on Livingston (2011): alcohol outlets