Master thesis

Master of Science HES-SO in Life Sciences

Orientation Viticulture and Enology

2017

Roman Alonso Jose Hab Yaczamac - Successful future building for a wine consulting start-up in a growing wine consulting market in Oregon. Supervised by Christian Maurer.

The wine industry in Oregon United States has had a continuous development in regards to vineyard plantation and wineries established since the 1970. The highest growth has been developing since 2011. So far in 2014 the total number of wineries has grown to 676 and the number of vineyards to around 1027. This data has led the author to consider a creation of a wine consulting start-up in Oregon.

The author with the assistance of the literature and a full market analysis of the global situation in Oregon has developed few hypotheses to be tested in the real market. The hypotheses with the highest success rate will then be adjusted after an initial survey to be implemented in the market in March 2017.

Sofia Rivier - Caractérisation comparée de la flore du vignoble selon différents modes d'entretien. Supervised by Matteo Mota.

A summary will soon be available.

Bruno Stump Ugarte - Impact of shipping and transporting conditions on Swiss wine. Supervised by Dr. Benoît Bach.

This work investigated the effects of extreme but realistic simulated shipping temperatures on the physical-chemical and sensorial composition of Swiss glass bottled wines sealed with different closures. The export simulation experiments were carried out over a period of seven days and analysis were performed at final time (just after experiment). Shipping and storage conditions included the following temperature modalities, optimal storage conditions(15ºC), extreme hot conditions (40ºC), and imitating the day/night effect conditions (15ºC-40ºC). The ability to protect of a tailor made thermal insulation quilt against temperature fluctuations was explored as a preventive measure to be implemented in the swiss wine export market.

Classic oenological parameters were monitored with reference methods as well as the microbiological aspect and physical state of the bottle. A thorough focus was done on three main closures and its effectiveness against detrimental temperatures. The sensorial facet was also analyzed and ranking task was chosen as a sensory descriptive profiling and ranking method combining a pre-established list of descriptors with the possibility for each trained panelist to add descriptors.

Analytical and sensorial results reflected differences amongst the different temperature modalities however physical defects like increase in turbidity for white wines, pushed corks and leakages were the most common. After the export simulation, all wines regardless the closure were characterized by a slight loss of free SO2 and a difference in total anthocyanin content for red wines. All the closures tested showed to have little influence in protecting wine from negative temperature effects. The thermal insulation quilt proved to be effective in lowering the temperature shocks and average during an export simulation thus preventing physical defects from happening. More research should be conducted in this field.

2016

Florian Favre - Key Performance Indicators for Solid Winery Management. Supervised by Christian Maurer.

This study, conducted in 2014 to 2016, proposes a new diagnostic tool to analyze key performance indicators for companies active in the viticulture and enology industry. Firstly, key performance indicator hypotheses were defined. Conducting interviews with focus groups helped to determine the key activities of a winery. An online questionnaire consisting of 44 questions yielded 77 responses from winery managers.


A principal component analysis revealed trends in practices used by managers and compared them to the wineries financial outcome. Additional statistical and visual analysis led to quantitative information on other indicators and trends. The 14 main indicators are presented below in a KPI. The purpose of this study is to create a visual business model tool that is specific, measurable, relevant and time-bound (SMART) (Figure 48) and allows any business to become quickly evaluated and comparable. Figure 48 New business model -specific KPIs include the 14 of the study.


After collecting and incorporating information from numerous companies, we hope to consult with growers in order to improve problem areas while communicating good practices. It is important to note one of the shortcomings of this study as the sample size. The number of companies used to establish the limits of this tool was only 77 individuals while Switzerland has over 1600 SMEs in its wine industry alone.


The economic branch of Swiss wine is only at the dawn of its strategic and operational business management evolution. The future prospects of such a study are numerous. Further studies should look to refine this tool and clarify the boundaries of "excellent", "acceptable" and "potentially problematic", for each criterion. One way to achieve this would be to use the tool to scan a maximum number of companies. The next step is to relaunch the new benchmarking by means other than an online survey. A personal meeting with each manager would be a good solution to get more information including financial results.

Michel Reynolds - Specificity of innovative vegetal fibers for the reduction of pesticides and mycotoxins in Swiss wine. Supervised by Dr. Johannes Rösti.

The northern climatic conditions expose vineyards to significant pressure from fungal diseases. The most common treatments used to address this are based on active synthetic ingredients that can be transferred to the treated wine. Pesticides are often not considered appropriate treatments as they contain several active substances that are potentially dangerous to the health of the consuming public.

A separation technique based on activated vegetal fibers (AVF) has been developed which reduces pesticide residues in wines. It is effective and has a minimal effect on the quality of the treated wine (Lempereur & al., 2014). The composition of AVF is such that it is possible to measure the threshold of AVF in quantities below 0.1 g/L when in an aqueous solution or a hydro-alcoholic solution.

A selection of pesticides regularly used and often found in Swiss wines were used in this study to obtain the Freundlich isotherms necessary to calculate the following absorption capacities of Fenpropidin : k = 1611 μg/g fiber and fluopyram k = 307 μg/g fiber. This showed that the rate of reduction of its active compounds is constant and not tied to their initial concentration. We analyzed solutions with different ratios of AVF to pesticides and found three different efficiency classes with reduction rates ranging between 80-100%, 50-80% and 0-50%, respectively. We also demonstrated that there was no competition effect between the various active substances found in liquid solutions.

Pre-industrial tests showed that filtration with AVF + Kieselguhr resulted in higher pesticide reduction rates than filtration with Kieselguhr alone. Such tests revealed no differences in chemical or organoleptic analysis. A laboratory pilot filter was prepared that acted both as a Freundlich isotherm treatment and a pre-industrial filtration. This tool would offer wine producers a quick and easy way to assess the effectiveness of AVF filtering by showing pesticide reduction rates and organoleptic impact. Comparing wines filtered at different AVF concentrations showed that there was a positive correlation between pesticide reduction rates and the degree of AVF concentration in the fiber cake. These results suggest that the contact time between the AVF and the wine is a key factor in determining the  reduction rate. A sensory analysis showed that the longer a wine is in contact with the AVF, the higher the tannic perception (i.e., the wine demonstrating a dryer and rougher quality). It was not possible to compare AVF reduction rates and chemical and organoleptic analysis results between wine filtered with the laboratory pilot filter and wine filtered with a pre-industrial filter using the same concentrations of AVF because the contact times between wine and the AVF were different for the two types of filtration.

These experiments demonstrate the potential advantages of AVF's over other active materials such as Fluopyram and Fenpropidin. This is something which has not been studied to date. It seems that under the condition of our experiments, the contact time between the wine and the AVF was too short to transmit the paper taste that has been found in preindustrial taste tests (Lempereur et al., 2014) and obtain an optimal reduction rate. Our results also suggest that different smells can be transmitted to the wine depending upon the duration of the contact time between the wine and the AVF.

There are other possible uses of AVF’s such as tangential filtration with a batch fed by AVF's and percolation, but the amount of contact time will remain a critical factor. Adding deodorization of the AVF by UV or ozone as a step in the AVF fabrication process might produce interesting results.

2015

Jordan Crabtree - Management of the heterogeneous quality of a high amount of vineyards in a cooperative winery. Supervised by Jean-Philippe Burdet.

Cave de Bonvillars is a wine-cooperative in the Bonvillars wine region in Switzerland. In recent years the winery has been struggling to get the quality of grapes from the growers needed to produce quality wines. Representatives of the winery approached Changins in hopes to discover new methods for pricing grapes based on their level of quality, but also methods to try to improve the quality of the overall grape production. Crabtree’s model was created to integrate different aspects of the cooperative starting from using technical grape quality parameters, and the assessing the quality of viticulture practice using a Vineyard Scorecard to score the level of grape quality. The grape quality score is then used to calculate a price/kg to be paid to each grower based on the quality of grapes they produced. A system to account for the efforts of each grower to ensure a quality grape production is also to award cooperation with the winery’s aim to improve grape quality. The model as whole serves as a system to give incentives to go the extra mile by setting certain very feasible standards to be met to prevent the reoccurrence of low quality grape production.

Williams Metz - Use of high-resolution airborne imagery to define the spatial structures of a vineyard. Supervised by Dr. Stéphane Burgos.

This paper investigates the use of an unmanned aerial vehicle (UAV) for non-spectral focused remote sensing applications. Presented is a methodology for acquisition and image processing in order quantify physical structures within vineyards through shadow and surface model analysis. Through use of a SenseFly eBee UAV, 223 aerial images were used to create an orthomosaic and digital surface model (DSM). The orthomosaic was used to analyze vine shade as an indicator of sun intercept. The DSM was manipulated in order to remove slope, and then used to predict relative vine size and grass height. The digital measurements were then related to physical, field-based measurements. The results demonstrate the potential of the method and outline a number of considerations for improving the accuracy of the method.

Danielle Widmer - Gärsteuerung mittels FT-NIR bei konstanter Zuckervergärrate – Einfluss auf Hefeviabilität und Kinetik stressbedinger Gärungsnebenprodukte. Supervised by Dr. Ramón Mira de Orduña Heidinger.

Die Entwicklung einer in der aktuellen Weinbereitung neuen Fermentationsmethode (Fed-Batch) ermöglicht es durch Einsatz von FT-NIR Spektroskopie und Prozessautomatisierung die Überwachung der alkoholischen Gärung zu automatisieren. Das System liefert zu jedem Zeitpunkt der Fermentation Informationen zu Verlauf und Konzentration der wichtigsten Fermentationsparameter Glukose, Fruktose und Ethanol. Diese Informationen erlauben es, Fed-Batch Fermentationen bei konstant niederiger Zuckerkonzentration durchzuführen und den osmotischen Stress der Hefe Saccharomyces cerevisiae, und dementsprechend die Produktion von unerwünschten Gärungsnebenprodukten wie Essigsäure und Acetaldehyd, zu reduzieren und Gärproblemen vorzubeugen.

In der vorliegenden Arbeit wurde die automatisierte Fed-Batch Methode für die Vinifikation eines Weissweines unter Praxisbedingungen angewandt. Die Populationsdynamik von Saccharomyces cerevisiae, wie auch der Apiculatus Hefen wurde während der Gärung der Batch bzw. Fed-Batch Vinifikationen verfolgt. Weiter wurden Proben genommen um organische Säuren, Glyzerin, Acetaldehyd, Aminosäuren und Ammonium zu analysieren. Die fertigen Weine wurden schliesslich durch das Expertenpanel der Hochschule mittels Diskriminationstest (2/5) und deskriptivem Test (freier Kategorisierung) auf Unterschiede getestet und beschrieben.

Die letzten Wochen vor der Ernte waren regnerisch und führten zu hohem Krankheitsdruck. Die traditionellen Batch Fermentationen waren durch einen signifikant höheren Titer an Apiculatus Hefen gekennzeichnet und wiesen in der deskriptiven Analyse entsprechen höhere Konzentrationen an Essigsäure und Ethylacetat auf. Der Apiculatus-Titer war in den Fed-Batch Fermentationen 1-2 Potenzen niedriger was bei der Beurteilung des Sensorikpanels zu sinifikant fruchtigeren und frei von Fehlern beurteilten Weinen führte. Die chemischen Analysen bestätigten die unterschiedliche Dynamik verschidener Gärungsnebenprodukte zwischen den Batch und Fed-Batch Vinifikationen. Die Gehalte an Acetaldehyd waren tiefer in den Fed-Batch Weinen. Ein besonderes Merkmal war die Abwesenheit von Essigsäure in Fed-Batch Weinen.

Der neue Ansatz der Fed-Batch Vinifikation stellt eine interessante Alternative zur traditionellen Batch Vinifikation dar. Dies gilt im Speziellen für Moste mit hohem Zuckergehalt, wo der osmotische Stress von Saccharomyces cerevisiae signifikant reduziert werden kann, aber auch für Mosts aus Trauben mit hohem Krankheitsdruck, da die Vermehrung der Apiculatus Hefen deutlich reduziert werden kann. Bei gleichem Most und Hefestarter führte die Anwendung der Fed-Batch Methode zu fundamentalen Änderungen der Hefeökologie und -stoffwechsel, und verursachte hierdurch auch entsprechende sensorische Unterschiede. Die Studie unterstreicht das praktische Potenzial der Fed-Batch Methode in der Önologie.