Impact of Yeast Strain on Ester Levels and Fruity Aroma Persistence during Aging of Bordeaux Red Wines

The impact of yeast and lactic acid bacteria strains on the fruity aroma of red wines was investigated by sensory and analytical strategies. The ester composition of four different Bordeaux red wines was quantified by HS-SPME-GC/MS. These wines, made with selected yeast and bacteria strains, were investigated at the end of alcoholic fermentation and regularly until 12 months of aging, during 2011 and 2012 vintages. Sensory analyses of wines after 3 and 12 months of aging revealed significant differences with regard to yeast strains. Bacteria seemed to have only a slight impact on changes in aromatic profile. Ester levels were strongly influenced by yeast strain and very little affected by malolactic fermentation and aging. Differences and similarities between sensory data and ester profile are discussed. This study highlights the importance of yeast strains in red winemaking. Their sensory impact remains despite the other vinification steps after alcoholic fermentation

The complexity of wine: clarifying the role of microorganisms

The concept of wine complexity has gained considerable interest in recent years, both for wine consumers and wine scientists. As a consequence, some research programs concentrate on the factors that could improve the perceived complexity of a wine. Notably, the possible influence of microbiological factors is particularly investigated. However, wine complexity is a multicomponent concept not easily defined. In this review, we first describe the actual knowledge regarding wine complexity, its perception, and wine chemical composition. In particular, we emphasize that, contrary to expectations, the perception of wine complexity is not related to wine chemical complexity. Then, we review the impact of wine microorganisms on wine complexity, with a specific focus on publications including sensory analyses. While microorganisms definitively can impact wine complexity, the underlying mechanisms and molecules are far from being deciphered. Finally, we discuss some prospective research fields that will help improving our understanding of wine complexity, including perceptive interactions, microbial interactions, and other challenging phenomena