GEISENHEIM INSTITUTE WINE FERMENTATION OF COOL-CLIMATE DEVELOPMENT SENSORY VARIETALSDURING GEISENHEIM INSTITUTE GERMANY, APRIL 24, 2009 GERMANY, APRIL 24, 2009 SENSORY DEVELOPMENT OF COOL-CLIMATE VARIETALS DURING WINE FERMENTATION MALOLACTIC FERMENTATION IN WINE FERMENTATION MALOLACTIC Cover design: Bruno Loste design: Bruno Cover GEISENHEIM INSTITUTE, GERMANY, APRIL 24, 2009 SENSORY DEVELOPMENT OF COOL-CLIMATE VARIETALS DURING WINE FERMENTATION PROCEEDINGS OF LES XXIes ENTRETIENS SCIENTIFIQUES LALLEMAND SENSORY DEVELOPMENT OF COOL-CLIMATE VARIETALS DURING WINE FERMENTATION FOREWORD his year, the XXIes Entretiens Scientifiques Lalle- – it is all about recognizable typicality, related to unique mand focused on cool-climate varietals and how vineyards or regions – and the winemaker influences it via T to understand their sensory development as well viti-vinicultural decisions. as the impact wine fermentation has on their properties. Dr. Yves Le Fur, from the UMR FLAVIC, INRA-ENESAD – The meeting was held in collaboration with the Geisen- Université de Bourgogne group, echoed some of the same heim Research Centre, which celebrated the 115th anni- sentiment regarding terroir expression when he presented versary of the Geisenheimer Hefe-Reinzucht-Station. The their work on the definition of the unique sensory space meeting gathered some of the top scientists in the field to of Chardonnay wines by wine experts, by having wines present this topic to an international and local crowd. It defined by exemplary scores. was also an opportunity to bestow the Lallemand award on the most deserving student at the Geisenheim Research From the perspective of malolactic fermentation (MLF), Centre in the field of Wine Microbiology. Daniel Ger- Ramón Mira de Orduña, from Cornell University, present- hards, a graduate student, was the proud recipient of this ed on acetaldehyde, which is a small and highly reactive award for his work The investigation of the metacaspase molecule that has chemical, sensory and microbiological YCA1 for better detection of apoptosis in Saccharomyces significance in wine, although lately there has been con- cerevisiae during alcoholic fermentation of grape must. troversy regarding its negative impact on human health. Professor Manfred Grossmann, head of the Microbiology MLF was also the focus of Tatjana Košmerl, from the Uni- and Biochemistry section at the Geisenheim Research versity of Ljubljana in Slovenia. The work of her team Centre, opened the meeting with a comprehensive review showed that the use of different lactic acid bacteria start- of the diversity of current research at our host institution. ers not only had an impact on the course of MLF in Welsh Riesling and Sauvignon, but on their chemical composi- Dr. Chris Curtin, from the Australian Wine Research In- tion as well. stitute, presented the first results of trials done on Char- donnay from Margaret River, a relatively cool region in The sensory impact of yeast and bacteria are now estab- Western Australia, fermented with different yeasts, and lished facts, and as ongoing research results allow us to how that would impact the production of specific sensory understand the mechanisms behind those processes wine- compounds, including thiols, and consumer preference. makers can benefit from this information. The prime goal of our interest in research is to translate scientific results Based on the research at the DLR Rheinpfalz in Germany into improvements in wine quality, and our association in the laboratory of Ulrich Fischer, their study on yeast and with the Geisenheim Research Centre for this event re- its role in terroir expression was presented. Their prelimi- flects this cooperative spirit. nary work showed that terroir goes beyond individuality – 3 – SENSORY DEVELOPMENT OF COOL-CLIMATE VARIETALS DURING WINE FERMENTATION 115TH ANNIVERSARY OF THE GEISENHEIM RESEARCH CENTRE Prof. Dr. Manfred GROSSMANN Forschungsanstalt Geisenheim/ Research Institute Geisenheim Fachgebiet Mikrobiologie und Biochemie/ Department Microbiology and Biochemistry Von-Lade-Strasse 1 D-65366 Geisenheim The Geisenheim Pure Yeast Culture Centre: At the Geisenheim Research Centre, our microbiology and “Addicted” to Wine Science and Production for biochemistry section is now one of a total of 13 sections. Generations The premier advantage of Geisenheim is that we can work along the entire wine production chain, from the grape When the French scientist Louis Pasteur published his wine up to market research. Through this, we are often in- breathtaking research results about yeasts and bacteria volved in interdisciplinary projects where, for example, a found in wines, determining the quality of the winemak- special microbiological research field (sluggish and stuck ing process in the second half of the 19th century, he in- fermentations) is the focus, and other sections, like viticul- spired researchers in many countries to follow his foot- ture and wine technology, are colleagues, not rivals as in steps in the challenging field of wine microbiology. other projects. The type of project we work on that is most It might be surprising to realize that Hermann Müller, appreciated are those where international institutions or now known as a breeder of the white grape variety “Mül- companies related to the wine business join us to solve ler Thurgau,” was the first person in Geisenheim to start current problems in the wine industry or to provide new – in 1876 – isolating wine yeasts of different origins and methods using special microorganisms to meet market/ checking their potential as pure yeast cultures for wine consumer demands. production. At the time, he was working in the newly es- Our research work in the microbiology and biochemistry tablished “Königliche Lehranstalt für Obst- und Weinbau section currently focuses on: Geisenheim” (Royal Education Centre for Pomology and Viticulture), inaugurated by the Prussian King in 1872. • Elucidating impact factors and microbial pathways de- livering pleasant (thioles) or unpleasant aroma com- Julius Wortmann, who followed Müller, established the pounds in different quantities “Geisenheimer Hefereinzucht Station” in 1894. However, • Developing new techniques, including molecular biol- looking back in history one has to realize that the wine ogy tools, to predict and control fermentations, as well people at that time were not ready for the sterile propa- as the resulting alcohol levels gation of a small volume of liquid yeast into hundreds of litres of starter culture, or for controlling the course • The interactions among different yeasts, and between of fermentation by using a microscope. Moreover, the yeasts and bacteria, and the resulting aroma profiles world economic crisis and two world wars dramatically • Classic breeding and genetic engineering of yeasts, and hindered the development of yeast technology. Although risk assessment studies. wine microbiology as part of wine science has grown im- Last but not least, it is our prime goal to transform sci- mensely since the 1950s, the ultimate breakthrough in the entific results into improvements in wine quality and the usage of pure yeasts occured when the drying process for health of wine consumers. We are truly honoured to host fresh yeast was optimized to meet the needs of the wine the Lallemand technical conference in 2009. industry. – 4 – SENSORY DEVELOPMENT OF COOL-CLIMATE VARIETALS DURING WINE FERMENTATION CONTENTS YEAST MODULATION OF COOL-CLIMATE MICROBIOLOGICAL ACETALDEHYDE KINETICS: CHARDONNAY SENSORY PROFILES AND CURRENT RESULTS AND MANAGEMENT IN THE CONSUMER PREFERENCES .......................................7 CONTEXT OF SIMULTANEOUS ALCOHOLIC AND Chris CURTIN, Brooke TRAVIS, Patricia OSIDACZ, MALOLACTIC FERMENTATIONS .............................35 Robyn KIEVIT, Belinda BRAMLEY and Leigh FRANCIS Sandra CHRISTEN, Nick JACKOWETZ and Ramón MIRA DE ORDUÑA IMPACT OF YEAST AND TERROIR DIVERSITY ON THE SENSORY PROPERTIES OF GERMAN RIESLING ......13 EVOLUTION OF AROMA COMPOUNDS DURING Ulrich FISCHER, Andrea BAUER, Stephan SOMMER, THE MALOLACTIC FERMENTATION OF THE Sebastian GANSS, Hans-Georg SCHMARR, Sascha COOL-CLIMATE VARIETIES WELSH RIESLING AND WOLZ and Anette SCHORMANN SAUVIGNON BLANC ..............................................41 Tatjana VRŠCAJˇ VODOŠEK, Irena KRALJ CIGIC,´ Matija STRLICˇ and Tatjana KOŠMERL SENSORY SPACE OF TYPICAL CHARDONNAY WINES AND OTHER WINES, AND ITS RELATION TO VOLATILE COMPOSITION .......................................................27 Yves LE FUR, Julien JAFFRE and Dominique VALENTIN – 5 – SENSORY DEVELOPMENT OF COOL-CLIMATE VARIETALS DURING WINE FERMENTATION YEAST MODULATION OF COOL-CLIMATE CHARDONNAY SENSORY PROFILES AND CONSUMER PREFERENCES Chris CURTIN, Brooke TRAVIS, Patricia OSIDACZ, Robyn KIEVIT, BELINDA BRAMLEY and Leigh FRANCIS The Australian Wine Research Institute P.O. Box 197, Glen Osmond SA 5064, Australia Introduction (2005), whereby compositional data were used to gener- ate an aroma model for a good example of Burgundian The term “quality” when applied to wine evokes a feel- Chardonnay. Wines previously considered intermediate ing that what you are about to taste will meet and hope- in their typicality within this context were rated as good fully exceed your expectations. If you limit the scope to examples when as few as 10 aroma compounds were add- a single Chardonnay wine style, experienced tasters can ed. Thus an experienced taster’s opinion of Chardonnay broadly agree on what these expectations are, even in quality may be