Compositional and Sensory Analysis of Finger Lakes Riesling

Compositional and Sensory Analysis of Finger Lakes Riesling
Author: Rebecca Erin Nelson
Publisher:
Total Pages: 170
Release: 2011
Genre:
ISBN:

As the wine world continues to globalize, and industry competition grows, wine regions have increasingly focused on promoting one or two grape varietals which result in consistently expressive wines that best represent the viticultural area. A variety of studies have concentrated on defining regional cultivar typicity not only to enhance marketing techniques, but also to increase the understanding of a specific cultivar within the region from viticultural, enological, and sensorial perspectives, and findings may be relevant to the entire field. The Finger Lakes region of New York State has put itself on the world wine map through production of Rieslings with definitive sensory character. Preliminary assessments also suggest unique sensory profiles exist in the Rieslings according to which Finger Lake the grapes are cultivated. The sensory properties of Finger Lakes Rieslings, and the presence of subregional character, have not previously been investigated through rigorous, formal sensory analysis. This experiment sought to determine whether Riesling grapes grown along Keuka, Seneca, and Cayuga Lakes and from two distinct clones produced wines with unique sensory and compositional profiles. Six similar blocks of Riesling were selected to reduce effects of viticultural practices on compositional and sensory outcomes. Two sites, exclusively planted with clone 90 or clone 239, were selected from the east side of each lake. Viticultural treatments were standardized throughout the growing season. Inherent site and seasonal characteristics were recorded, and specific vine physiology and status measurements were collected from each block. Grapes were vinified, in duplicate lots from each site, by a standard winemaking protocol to yield two fermentation replicates. Instrumental analyses (GC-FID and GC-MS) were performed to quantify selected volatile aroma constituents of the Riesling wines. Generic descriptive analysis (DA) was performed on the wines by eleven panelists, screened for white wine consumption habits and sensory acuity. Sensory reference standards were developed during training and utilized along with intensity standards during orthonasal evaluation of the wines. Wines were also analyzed by HPLC for phenolic acids profiling. Statistical analyses of the volatile data showed that significant differences existed among some compounds. However, most of these differences were likely of no biological significance based on similarity of overall volatile profiles and vineyard site characteristics such as canopy light environment, vine water status, and crop load, factors which may impact wine quality. Monoterpene and TDN levels were at or below sensory threshold, and linalool was the only compound with apparent correlation to sensory data. DA panelists established 11 aroma attributes important to Finger Lakes Riesling wines. Wine aroma profiles were similar across vineyard sites, and two-way ANOVA results of lake, clone, and their interaction were not significant. Citrus, pineapple, linalool/floral, melon, and stemmy were among the descriptors present at the highest intensities. Phenolics data were characteristic of white wines as hydroxycinnamic acids and their tartrate esters dominated the profile. Higher concentrations of fertaric acid than coutaric acid were observed. While ANOVA showed significant results for lake, clone, and their interactions, clone had the strongest effect. These experiments indicate that sensory and aroma profiles of Riesling wines were similar despite differences in clonal material and growing conditions. However, the importance of seasonal growing conditions should not be overlooked as this experiment should be repeated over multiple years. The Riesling wines were also analyzed with less than six months of bottle age, and aging has the potential to impact wine differentiation. This sensory and volatile data is among the first to be reported for Riesling in the Finger Lakes. Riesling clone may be of interest to growers and winemakers due to effect on phenolic profile which may impact volatile stability and oxidative browning.

Sensory and Chemical Evaluation of Riesling, Chardonnay and Pinot Noir Fermented by Different Strains of Saccharomyces Cerevisiae

Sensory and Chemical Evaluation of Riesling, Chardonnay and Pinot Noir Fermented by Different Strains of Saccharomyces Cerevisiae
Author: Ann Dumont
Publisher:
Total Pages: 310
Release: 1994
Genre: Wine and wine making
ISBN:

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.

Ecological Survey of Spontaneously Fermented Riesling in the Finger Lakes

Ecological Survey of Spontaneously Fermented Riesling in the Finger Lakes
Author: Marie Guido-Miner
Publisher:
Total Pages: 194
Release: 2019
Genre:
ISBN:

Spontaneous fermentations are completed by a complex succession of non-Saccharomyces yeast species and S. cerevisiae strains that influence the final wine aroma and flavor profile. Regional yeast composition may help shape the wine characteristics typical in a region, a concept known as microbial terroir. To establish the yeast composition of Riesling grapes in the Finger Lakes American Viticultural Area (AVA), an ecological survey of vineyard and winery microbiome, with a particular focus on S. cerevisiae strains, was performed. Grapes, winery equipment, and spontaneous fermentations were sampled during the 2015 and 2016 vintages at three Finger Lakes AVA vineyards and the associated wineries. Yeast was isolated using culture-dependent methods, identified using the 5.8S internal transcribed spacer (ITS) rRNA region, and S. cerevisiae strains were characterized using a six-locus multiplex variable number of tandem repeat (VNTR) analysis. Species from the Aureobasidium, Candida, Hannaella, Hanseniaspora, Metschnikowia, Meyerozyma, Pichia, Rhodotorula, Saccharomyces, Torulaspora, Trigonopsis, Wickerhamomyces, Zygoascus, and Zyosaccharomyces genera were identified. Numerous unrelated native S. cerevisiae strains, and a small number of commercial strains, were commonly observed in fermentations. When commercial strains were present, they did not always become established or dominant in the fermentation, and never completely displaced the native strains. Several native S. cerevisiae strains are likely part of the regional microbiome and should be investigated further. The S. cerevisiae strains observed in fermentations appear to be influenced by regional and resident winery microbiome, and by vintage specific factors.

Managing Wine Quality

Managing Wine Quality
Author: Andrew G. Reynolds
Publisher: Woodhead Publishing
Total Pages: 0
Release: 2010-10-14
Genre: Technology & Engineering
ISBN: 9781782421443

Many aspects of both grape production and winemaking influence wine sensory properties and stability. Progress in research helps to elucidate the scientific basis of quality variation in wine and suggest changes in viticulture and oenology practices. The two volumes of Managing wine quality review developments of importance to wine producers, researchers, and students. The focus is on recent studies, advanced methods and likely future technologies. Volume 1 opens with chapters reviewing current understanding of wine aroma, colour, taste and mouthfeel. Part two focuses on the measurement of grape and wine properties. Topics covered include instrumental analysis of grape, must and wine, sensory evaluation and wine authenticity and traceability. The effects of viticulture technologies on grape composition and wine quality attributes are the subject of part three. Terroir, viticultural and vineyard management practices, fungal contaminants and grape processing equipment are among the areas discussed. Volume 2 opens with chapters reviewing the impact of different winemaking technologies on quality. Topics covered include yeast and fermentation management, enzymes, ageing on lees, new directions in stabilisation, clarification and fining of white wines and alternatives to cork in wine bottle closures. Managing wine sensory quality is the major focus of part two. Authors consider issues such as cork taint, non-enzymatic oxidation and the impact of ageing on wine flavour deterioration. The volume concludes with chapters on the management of the quality of ice wines and sparkling wines. Reviews current understanding of wine aroma, colour, taste and mouthfeel Details the measurement of grape and wine properties through instrumental analysis, must and wine, and sensory evaluation Reviews the impact of different technologies on wine quality

The Wine Bible

The Wine Bible
Author: Karen MacNeil
Publisher: Workman Publishing Company
Total Pages: 2408
Release: 2015-10-13
Genre: Cooking
ISBN: 0761187154

No one can describe a wine like Karen MacNeil. Comprehensive, entertaining, authoritative, and endlessly interesting, The Wine Bible is a lively course from an expert teacher, grounding the reader deeply in the fundamentals—vine-yards and varietals, climate and terroir, the nine attributes of a wine’s greatness—while layering on tips, informative asides, anecdotes, definitions, photographs, maps, labels, and recommended bottles. Discover how to taste with focus and build a wine-tasting memory. The reason behind Champagne’s bubbles. Italy, the place the ancient Greeks called the land of wine. An oak barrel’s effect on flavor. Sherry, the world’s most misunderstood and underappreciated wine. How to match wine with food—and mood. Plus everything else you need to know to buy, store, serve, and enjoy the world’s most captivating beverage.

Wine, Society, and Globalization

Wine, Society, and Globalization
Author: G. Campbell
Publisher: Springer
Total Pages: 281
Release: 2007-12-25
Genre: Business & Economics
ISBN: 0230609902

This collection of essays comprises a number of case studies from key wine-growing regions and countries around the world. Contributors focus on the development of the wine business and its overall importance and impact in terms of the regional and domestic economy and the international economy