Download or read book Chemical and Sensory Influences of Sur Lies on Chardonnay Wines written by Gregory Tazwell La Follette and published by . This book was released on 1991 with total page 350 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Sensory and Chemical Evaluation of Riesling Chardonnay and Pinot Noir Fermented by Different Strains of Saccharomyces Cerevisiae written by Ann Dumont and published by . This book was released on 1994 with total page 310 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fermentation of the grape must into wine is one of the most important steps in winemaking. Selected yeast strains of Saccharomyces cerevisiae have been used for many years to ensure complete and even fermentations. The formation of volatile compounds also occurs during fermentation and will influence the sensory perception of the wine. The main objective of the research was to study the sensory and chemical composition of 1992 Oregon Riesling, Chardonnay and Pinot Noir wines fermented with different commercial S.cerevisiae strains. In the first study, Free-Choice Profiling was used to study the sensory profiles of all three varieties after 7 and 20 months of aging. This method was used in order to utilize a panel of expert winemakers for the tastings. The sensory data analyzed through Generalized Procrustes Analysis showed that some strains were similar while others were different in terms of aroma and flavor at 7 months of age. After 20 months of aging, differences and similarities were still present although the sensory profiles were different from the young wines. This last finding showed that differences are still present after a period of aging. In the second study, the chemical composition of all three varieties and the volatile composition of selected wines of Riesling and Chardonnay were studied. In both white varieties, statistical differences in titratable acidity, residual sugar, volatile acidity and malate content resulted from fermentation with different yeast strains. The volatile composition was qualitatively similar, but some quantitative differences, as relative concentration, were found. Whether or not those differences had a sensory impact was not investigated. Results of the present study showed the need for further studies in order to understand the role of yeast in flavor development. Relationships between sensory profiles and volatile composition could help winemakers to understand the influence of a selected strain on a particular variety and to select yeast strains to optimize wine quality.
Download or read book Understanding Wine Chemistry written by Andrew L. Waterhouse and published by John Wiley & Sons. This book was released on 2016-08-29 with total page 485 pages. Available in PDF, EPUB and Kindle. Book excerpt: Wine chemistry inspires and challenges with its complexity, and while this is intriguing, it can also be a barrier to further understanding. The topic is demystified in Understanding Wine Chemistry, Special Mention awardee in the 2018 OIV awards, which explains the important chemistry of wine at the level of university education, and provides an accessible reference text for scientists and scientifically trained winemakers alike. Understanding Wine Chemistry: Summarizes the compounds found in wine, their basic chemical properties and their contribution to wine stability and sensory properties Focuses on chemical and biochemical reaction mechanisms that are critical to wine production processes such as fermentation, aging, physiochemical separations and additions Includes case studies showing how chemistry can be harnessed to enhance wine color, aroma, flavor, balance, stability and quality. This descriptive text provides an overview of wine components and explains the key chemical reactions they undergo, such as those controlling the transformation of grape components, those that arise during fermentation, and the evolution of wine flavor and color. The book aims to guide the reader, who perhaps only has a basic knowledge of chemistry, to rationally explain or predict the outcomes of chemical reactions that contribute to the diversity observed among wines. This will help students, winemakers and other interested individuals to anticipate the effects of wine treatments and processes, or interpret experimental results based on an understanding of the major chemical reactions that can occur in wine.
Download or read book Chemistry and Biochemistry of Winemaking Wine Stabilization and Aging written by Fernanda Cosme and published by BoD – Books on Demand. This book was released on 2021-02-10 with total page 258 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book, written by experts, aims to provide a detailed overview of recent advances in oenology. Book chapters include the latest progress in the chemistry and biochemistry of winemaking, stabilisation, and ageing, covering the impact of phenolic compounds and their transformation products on wine sensory characteristics, emerging non-thermal technologies, fermentation with non-Saccharomyces yeasts, pathways involved in aroma compound synthesis, the effect of wood chips use on wine quality, the chemical changes occurring during Port wine ageing, sensory mechanisms of astringency, physicochemical wine instabilities and defects, and the role of cork stoppers in wine bottle ageing. It is highly recommended to academic researchers, practitioners in wine industries, as well as graduate and PhD students in oenology and food science.
Download or read book The Impact of Fining on the Chemical and Sensory Properties of Washington State Chardonnay and Gew rztraminer Wines written by Melissa Sanborn and published by . This book was released on 2008 with total page 90 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Principles and Practices of Winemaking written by Roger B. Boulton and published by Springer Science & Business Media. This book was released on 2013-04-17 with total page 616 pages. Available in PDF, EPUB and Kindle. Book excerpt: This essential text and reference offers a complete guide to winemaking. The authors, all well-known experts in their field, concentrate on the process of wine production, stressing the chemistry, biochemistry, microbiology and underlying science of enology. They present in-depth discussion of every aspect of the wine production process, from the selection of grapes and preparation of the must and the juice, through aging, bottling and storage of finished wines. Novices and experienced winemakers alike will find this clearly written and expertly crafted book an indispensable source of practical instruction and information.
Download or read book The Chemical and Sensory Effects on White Wine During Short term Aging Due to the Use of Different Sparging Gases at Bottling written by Bret D. Hogan and published by . This book was released on 2014 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: "This study examined the role of bottle shock in a young white wine while also considering the use of different sparging gases at bottling. A sensory panel was trained on the descriptive analysis of white wine. A Verdhelho-Torrontes blend was bottled with the use of different sparging gases: argon, nitrogen, carbon dioxide, medical-grade air, and pure oxygen. The trained panel evaluated the wine sensorially over a period of 42 days, assessing the wine's aroma, taste, and mouthfeel. Chemical analyses were performed on the wine during this period. The different sparging gases played an important role in certain chemical properties of the wine, notably free SO2, total SO\2082, headspace O\2082, and dissolved O\2082. Sparging gas had little effect on the sensory profile of the wines in this study. Time after bottling, however, was a large driver of the sensory profile of the wines, suggesting that bottle shock is a real phenomenon"--Abstract.
Download or read book Wine written by Jokie Bakker and published by John Wiley & Sons. This book was released on 2011-11-30 with total page 453 pages. Available in PDF, EPUB and Kindle. Book excerpt: Wine Flavour Chemistry brings together a vast wealth of information describing components of wine, their underlying chemistry and their possible role in the taste, smell and overall perception. It includes both table wines and fortified wines, such as Sherry, Port and the newly added Madeira, as well as other special wines. This fully revised and updated edition includes new information also on retsina wines, rosés, organic and reduced alcohol wines, and has been expanded with coverage of the latest research. Both EU and non-EU countries are referred to, making this book a truly global reference for academics and enologists worldwide. Wine Flavour Chemistry is essential reading for all those involved in commercial wine making, whether in production, trade or research. The book is of great use and interest to all enologists, and to food and beverage scientists and technologists working in commerce and academia. Upper level students and teachers on enology courses will need to read this book: wherever food and beverage science, technology and chemistry are taught, libraries should have multiple copies of this important book.
Download or read book Effect of Sulfur Dioxide and Yeast Starter Culture on Chemical Composition and Sensory Quality of Chardonnay and Pinot Noir Wines written by Aurea Carrasco and published by . This book was released on 1995 with total page 366 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book New Classic Winemakers of California written by Steve Heimoff and published by Univ of California Press. This book was released on 2010-12-20 with total page 302 pages. Available in PDF, EPUB and Kindle. Book excerpt: "This book is intellectual eavesdropping for wine lovers. Steve Heimoff asks all the right questions, and then wisely lets the winemakers take center stage."—Paul Lukacs, author of The Great Wines of America
Download or read book Chemistry of Wine Flavor written by Andrew Leo Waterhouse and published by . This book was released on 1998 with total page 264 pages. Available in PDF, EPUB and Kindle. Book excerpt: Wine flavour chemistry is a complex and diverse field that ranges from the potently aromatic pyrazines to the complex polymeric tannins. Modern chemistry is now opening some doors to the mysteries of wine flavour, and this unique monograph is dedicated to current research developments. The book starts with the Riesling terpenes, which are responsible for floral aroma when new and the kerosene-like aroma that appears in old age, and with the chemically related norisprenoids found in Cabernet Sauvignon and Merlot. It includes three reports on flavours of microbial origin, particularly the effects of different yeast strains, and it looks at important factors in ageing, including acetalhyde, the contribution of oak, and problems with cork taint. It also explores in detail the relationship between winemaking techniques and the chemistry and taste attributes of phenolic compounds.
Download or read book Influence of Wine Components on the Chemical and Sensory Quality of Wines written by Charles Diako and published by . This book was released on 2016 with total page 154 pages. Available in PDF, EPUB and Kindle. Book excerpt: Wine is an alcoholic beverage containing numerous compounds that contribute to its overall quality. The overall objective of this dissertation was to examine the influence of matrix interactions in commercial red wines on the sensory and chemical properties of wines, and explore advanced methods of mathematical analyses of these data. In the first study, the influence of these matrix components and their interactions on wine quality was examined. Commercial Merlot wines (n=61) were evaluated for wine chemistry parameters, with the matrix components of interest identified as alcohol, tannin and mannoproteins. Sensory evaluation results showed complex interactions among tannins, alcohol and mannoproteins on the perception of most aromas, flavors, tastes and mouthfeel attributes (p0.05). Since human subjects vary in their sensory perceptions, panel reproducibility and precision was addressed. Panelists' variation in attribute evaluations was conceptualized as a linear operator called a bias matrix for feedback calibration and correction of panelists' evaluations. Results showed that the bias matrix corrected the panelist ratings of the samples, leading to higher reproducibility and precision. No significant differences (p0.05) were found between the original and corrected means. Predictive filtering showed that the panelists' corrected means for the attributes were closer to the predicted panel mean compared to their unfiltered means. The application of the electronic tongue for the assessment of wine quality was further explored. Strong correlations (r2>0.930) were reported between the electronic tongue and the sensory perceptions of sweet, sour, bitter, burning, astringent and metallic. Further research on the application of the electronic tongue to discriminate among wines and building predictive models was performed. Non-linear methods showed high discrimination among the commercial wines (90.1%), with high prediction accuracy of the electronic tongue output using the chemical parameters ([greater than/equal to sign] 90.0%). These results showed the dependence of the intensity of the electronic tongue signal on the chemical components of the wines. This dissertation demonstrated how wine matrix components influenced perception through suppression and enhancement of various sensory attributes. In addition, advanced methods of chemical and sensory data analysis were developed and validated. Results from this study will be useful for winemakers for wine quality optimization.
Download or read book The Sensory and Chemical Properties of Wines as Influenced by the Presence of Different Wine Bacteria and Yeasts written by Victoria Dawn Paup and published by . This book was released on 2021 with total page 156 pages. Available in PDF, EPUB and Kindle. Book excerpt: Wine quality is a complex concept that is greatly influenced by its sensory characteristics and chemical composition, and many factors can contribute or detract from quality. The overall objective of this dissertation was to examine microbiological factors and their influence on wine quality using sensory evaluation and analytical testing methods. In the first study, the ability of the electronic tongue and experienced sensory panelists to discriminate among wines inoculated with spoilage microorganisms over storage was evaluated. Merlot wine was inoculated with spoilage microorganisms, in particular Brettanomyces bruxellensis, Pediococcus parvulus, Acetobacter pasteurianus, and Lactobacillus brevis, and tested weekly. Results showed that the electronic tongue discriminated among the inoculated wine samples starting at Day 21 of storage, while the experienced sensory panelists were unable to discriminate until Day 28. Therefore, the electronic tongue was demonstrated to be a useful tool for early detection of wine faults. In the second study, the influence of storage on the sensory and chemical characteristics of wines made with pectinase-producing non-Saccharomyces yeasts (NSY). The addition of NSY in Merlot wine increased cherry flavor over storage (p 9́Þ 0.05), an attribute often associated with wine quality. Additionally, significant differences were observed in pH and glycerol concentration in the wine. Some NSY that produce pectinase have been shown to increase polysaccharide concentrations which can improve mouthfeel characteristics. Building on this, providing sufficient substrate (pectin) may increase the activity of this enzyme. Therefore, the final study evaluated the influence of pectinase producing NSY on the sensory and chemical characteristics of wined with varying amounts of pectin. In both red and white wine, significant differences (p 9́Þ 0.05) were observed in the chemical parameters, in particular pH and D-galacturonic acid; however minimal differences were found in the sensory characteristics. Overall, this research advanced the understanding of how wine quality is affected by different wine microorganisms. In particular, new sensory and analytical methods for more rapid wine fault detection were developed, and a deeper understanding of the potential utilization of pectinase producing NSY to elicit chemical and sensory change was found.
Download or read book Wine Chemical and Sensory Attributes Influenced by Wine Glass Shape written by Gregory Dean Hirson and published by . This book was released on 2009 with total page 64 pages. Available in PDF, EPUB and Kindle. Book excerpt: The aroma of a wine in a glass is determined by the composition of the headspace in the glass above the wine and the concentration of the headspace components. Anecdotal evidence as well as peer-reviewed research has shown that glass shape can affect the sensory properties of a wine, yet little is known about the chemical composition of the glass headspace. The headspace compositions of two wines (Pinot noir and Gewurztraminer) in five glasses were monitored for peak area of 11-12 compounds, depending on the wine. The headspace composition was determined using solid phase micro-extraction (SPME) with a divinylbenzene - carboxen polydimethyl-siloxane (DVB/CAR/PDMS) fiber coupled to gas chromatography-mass spectrometry (GC-MS). Headspace compositions were monitored at three different equilibration times of 0, 5, and 10 minutes. Glass shape parameters cuppa height, glass capacity, and the ratio of maximum diameter to opening diameter (Dratio) were found to be important predictors of headspace concentration at five and ten minutes of equilibration. Glass shape parameters could not be used to accurately predict headspace volatile concentrations at zero minutes of equilibration. Varying glass shape was found to modulate overall aroma intensity as well as fruity and hot (ethanol) intensities, consistent with previous research. While correlations between chemical constituents in the headspace and sensory properties of the wine in different glasses could not be well characterized, Glass WW, a white wine glass, with the highest headspace concentrations for many compounds showed the lowest total aroma intensity, suggesting that higher concentrations of sub threshold components could be interfering with the perception of very low concentration, odor-active volatiles.
Download or read book Influences of Viticultural Treatments on the Sensory and Chemical Characteristics of Cabernet Sauvignon Wines written by Hua Chen and published by . This book was released on 2006 with total page 524 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Exploration Into the Influence of Malolactic Fermentation Parameters and Pre fermentation Juice Treatment on Chardonnay Mouthfeel written by Anthony Sereni and published by . This book was released on 2016 with total page 102 pages. Available in PDF, EPUB and Kindle. Book excerpt: Mouthfeel is one of the most important quality parameters of Chardonnay wines. Malolactic fermentation (MLF) is an important process in wine production, and influential to wine mouthfeel, with the reduction in acidity being particularly important for cool climate wines that generally have higher acidity such as Chardonnay. MLF is typically induced by the addition of Oenococcus oeni after the completion of the alcoholic fermentation (AF) but can occur concurrent with AF by inoculating O. oeni simultaneously with the fermentative yeast Saccharomyces cerevisiae. We investigated the effect of MLF inoculation timing as well as the temperature of MLF and the presence of the non-Saccharomyces yeast Torulaspora delbrueckii on Chardonnay wine mouthfeel. Chardonnay wines were produced in 2014 with AF and MLF inoculated for simultaneous or sequential fermentations, and temperatures 15 and 21°C, with or without the addition of T. delbrueckii. Mouthfeel attributes of the wines produced were assessed by a winemaker panel, using Napping® and Ultra-flash profiling. Significant differences in mouthfeel perception were found based on timing and inoculation conditions, as well as between temperatures. Treatment type and temperature also effected the chemical composition of finished wines. Additionally, there are many interactions that occur between taste and aroma that may impact mouthfeel perception. This led us to investigate whether the aroma fraction of Chardonnay wine should be considered when investigating relationships between chemical composition and sensory perception of mouthfeel. Chardonnay wines were determined to have mouthfeel differences by altering the fermentation temperature of the alcoholic and malolactic fermentation as well as the timing of MLF and the presence of a non-Saccharomyces yeast during AF. Napping® and Ultra-flash-profiling were conducted using a panel of white winemakers. Each procedure was conducted twice: once with retro-nasal aroma and once without retronasal aroma. Napping® results showed that retronasal aroma impacted mouthfeel perception. Ultra-flash profiling displayed similar descriptive terms used with and without retronasal aroma, but terms were not consistently used for the same wine treatments with and without retronasal aroma. It is unclear if these differences are due to interactions or due to associated learning. These results suggest that for some mouthfeel terms the volatile fraction is playing a role and to establish relationships with chemical composition and mouthfeel perception it is important to consider both the volatile and nonvolatile wine fractions. We then investigated the impact of pre-fermentation juice treatments on mouthfeel characteristics of Chardonnay wine. Chardonnay grapes were harvested from Oregon State University’s vineyard in September, 2015. After destemming and pressing the juice was subjected to various treatments. These treatments included high, medium, and low turbidity level, as well as hyper-oxidation, two-hour skin contact, and two-hour skin contact + hyper-oxidation. All treatments went through alcoholic and malolactic fermentations. Total phenolics and hydroxycinnamic acids differed between skin contact and hyper-oxidation treatments. Wines that underwent hyper-oxidation contained the lowest total phenolics. Hyper-oxidation following skin contact reduced total phenolics but retained more than the hyper-oxidation treatment. Sensory analysis using citation by frequency procedure showed that all treatments modified the mouthfeel of finished wines. However, chemical analysis did not fully elucidate the cause of these differences. Pre-fermentation juice treatments can be utilized to develop stylistic differences in finished Chardonnay wine. The combined findings of this research demonstrate the usefulness of various enological practices to influence the sensory qualities of a Chardonnay wine, as well as emphasizing the importance of retro-nasal aroma’s influence on the mouthfeel experience of Chardonnay wine.
Download or read book Sensory and Chemical Effects of Cross Flow Filtration and Pumping on White and Red Wines written by Peter Andrew Buffon and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: In the world of modern vinification, cross flow filtration and pumping are widely used. In the absence of systematic studies examining the effects of these unit operations on the resulting wine, winemakers are sometimes reluctant to use them to process their wines. Because cross flow filtration can not be accomplished without pumping, both of these unit operations were studied . Cross flow filtration is an increasingly common post-fermentation process in the wine industry. Because of the nature of the membranes used in this process, our hypothesis was that cross flow filtration would not have a significant impact on the sensory or chemical properties of either white or red wines. To investigate this, a California white wine blend and a California red wine blend were filtered in three 570 L lots using a Bucher Vaslin cross flow unit with a nominal 0.22 micron polyethersulfone membrane. The unfiltered control was sent directly to the bottling line without filtration. Panelists evaluated the wines nine times during an eight-month descriptive analysis panel with replicated tasting at each time point. UV-VIS spectrophotometry and the Adams-Harbertson assay were used to determine color and phenolic content of the filtered and unfiltered wines respectively. The effect of filtration was found to be significant for one sensory attribute out of 16 total measured in the white wine. Similar analysis for the red wines indicated that six sensory attributes were significantly different out of 16 total in the red wine. Unfiltered red wines were found to be higher in earthy, grassy, oak, and smoke aromas compared to filtered wines and lower in mixed berry and stone fruit aromas compared to the filtered wines, but only after two months in bottle. Cross flow filtration was found to have a stabilizing effect on the sensory profile of both wines. For both red and white wines, there were significant changes in color and phenolic profile with filtration, but it is not clear, especially for red wines, that the changes in phenolic compound concentration were large enough to be detected sensorially.The transfer of must, juice, and wine is a necessary process in vinification at various points from grape receiving through bottling. Pumps are among the most important pieces of equipment used to move wine from one place to another in commercial wineries. However, there has been a general lack of systematic data generated to assess the effect of pumping on the chemical and sensory properties of wine. These effects, if found, could be due to oxygen pickup during pumping, or some other mechanism of converting mechanical energy to changes in wine composition. To investigate this, a white wine blend and a red wine blend were pumped through a closed loop system at two different run times. Three different pumps were used in the experiment, a centrifugal pump, a flexible impeller pump, and a progressive cavity pump. This resulted in six treatments each for the white and red wines. The entire experiment was carried out in duplicate. A full sensory descriptive analysis panel was conducted on the wines using a ballot-trained panel. UV-VIS spectrophotometery and the Adams-Harbertson assay were used to determine color and phenolic content of the pumped and unpumped wines, respectively. Panelists were not able to differentiate pumped wines from the control, and additionally progressive cavity, flexible impeller, or centrifugal pumped wines from each other. Although statistically significant color differences were found between red wine treatments, these differences were less than 2% and no statistically significant phenolic differences were observed. Oxygen pickup was observed in the progressive cavity pump treatment, but relatively little was observed in the flexible impeller or centrifugal pump treatments. In summary, pumping caused little to no chemical or sensory changes in the experimental wines.
