Winemaking

About: Winemaking is a research topic. Over the lifetime, 2604 publications have been published within this topic receiving 71180 citations. The topic is also known as: vinification.

Tailoring wine yeast for the new millennium: novel approaches to the ancient art of winemaking

Abstract: Yeasts are predominant in the ancient and complex process of winemaking. In spontaneous fermentations, there is a progressive growth pattern of indigenous yeasts, with the final stages invariably being dominated by the alcohol-tolerant strains of Saccharomyces cerevisiae. This species is universally known as the ‘wine yeast’ and is widely preferred for initiating wine fermentations. The primary role of wine yeast is to catalyze the rapid, complete and efficient conversion of grape sugars to ethanol, carbon dioxide and other minor, but important, metabolites without the development of off-flavours. However, due to the demanding nature of modern winemaking practices and sophisticated wine markets, there is an ever-growing quest for specialized wine yeast strains possessing a wide range of optimized, improved or novel oenological properties. This review highlights the wealth of untapped indigenous yeasts with oenological potential, the complexity of wine yeasts’ genetic features and the genetic techniques often used in strain development. The current status of genetically improved wine yeasts and potential targets for further strain development are outlined. In light of the limited knowledge of industrial wine yeasts’ complex genomes and the daunting challenges to comply with strict statutory regulations and consumer demands regarding the future use of genetically modified strains, this review cautions against unrealistic expectations over the short term. However, the staggering potential advantages of improved wine yeasts to both the winemaker and consumer in the third millennium are pointed out. Copyright # 2000 John Wiley & Sons, Ltd.

Yeast and its Importance to Wine Aroma - A Review

Abstract: The most mysterious aspect of wine is the endless variety of flavours that stem from a complex, completely non-linear system of interactions among many hundreds of compounds. In its widest sense, wine flavour refers to the overall impression of both aroma and taste components. Aroma is usually associated with odorous, volatile compounds; the bouquet of wine refers to the more complex flavour compounds which evolve as a result of fermentation, elevage and ageing. With the exception of terpenes in the aromatic grape varieties and alkoxypyrazines in the herbaceous cultivars, perceived flavour is the result of absolute amounts and specific ratios of many of these interactive compounds, rather than being attributable to a single "impact" compound. Without underestimating the complexity of these interactive effects or negating the definitive role played by the accumulated secondary grape metabolites in the varietal character of wine, this review will focus mainly on the contribution of yeast fermentation to the sensorial quality of the final product. Yeast and fermentation conditions are claimed to be the most important factors influencing the flavours in wine. Both spontaneous and inoculated wine fermentations are affected by the diversity of yeasts associated with the vineyard and winery. During the primary alcoholic fermentation of sugar, the wine yeast, Saccharomyces cerevisiae, together with other indigenous non-Saccharomyces species, produce ethanol, carbon dioxide and a number of by-products. Of these yeast-derived metabolites, the alcohols, acetates and C4-C8 1tfatty acid ethyl esters are found in the highest concentration in wine. While the volatile metabolites contribute to the fermentation bouquet ubiquitous to all young wines, the production levels of these by-products are variable and yeast strain specific. Therefore, this article also highlights the importance of untapping the hidden wealth of indigenous yeast species present on grapes, and the selection and genetic development of yeast starter culture strains with improved flavour profiles. In the future, some winemakers may prefer to use mixtures of indigenous yeast species and tailored S. cerevisiae strains as starter cultures to reflect the biodiversity and stylistic distinctiveness of a given region. This will help winemakers to fullfil the consumer's demand for individual wines with intact local character and to ensure the survival of wine's most enthralling aspect - its endless variety.

Principles and Practices of Winemaking

Abstract: Preface. Introduction. Viticulture for Winemakers. Preparation of Musts and Juice. Yeast and Biochemistry of Ethanol Fermentation. Red and White Table Wines. Malodactic Fermentation. The Fining and Clarification of Wines. The Physical and Chemical Stability of Wine. Microbiological Spoilage of Wine and its Control. The Maturation and Aging of Wine. The Bottling and Storage of Wines. The Role of Sulfur Dioxide in Wine. Must, Juice and Wine Transfer Methods. Heating and Cooling Applications. Juice and Wine Acidity. Preparation. Analysis and Evaluation of Experimental Wines. Appendixes. Glossary

Wine Science: Principles and Applications

Abstract: (Section Headings): Introduction. Grapevine Origin, Breeding and Cultivars. Grapevine Structure and Function. Vineyard Practice. Site Selection and Climate. Chemical Constituents of Grapes and Wine. Fermentation. Post-Fermentation Treatment and Processing. Some Specific and Unique Wine Styles. Wine Laws, Authentication and Geography. Sensory Perception and Wine Assessment.

Concentration of the Phytoalexin Resveratrol in Wine

Abstract: Resveratrol is a phytoalexin found in grapes. Recent research had shown that orally administered resveratrol lowered lipid levels in the liver of rats. Wine had been shown to lower serum lipid levels in humans. The concentration of resveratrol was measured in selected wines using HPLC and spectrophotometry. Geographical origin, variety, growing methods, and winemaking procedures all seemed to affect resveratrol concentration. Analysis of wines indicated that resveratrol may be the active ingredient in wines causing reduction of serum lipids.