MALOLACTIC FERMENTATION

Malolactic fermentation (MLF) is an integral step in red winemaking, which not only is wine de-acidification, as it will also influence the composition of volatile fermentation-derived compounds with concomitant effects on wine sensory properties and the wine color profile. Long-established winemaking protocols for MLF induction generally involve inoculation of bacteria starter cultures post-alcoholic fermentation, however, more recently there has been a trend to introduce bacteria earlier in the fermentation process. Co-inoculation greatly reduces the overall fermentation time, and the rate of alcoholic fermentation is generally not affected by the presence of bacteria. In addition, the fermentation-derived wine volatiles profile is distinct in wines where bacteria were inoculated at a later stage of alcoholic fermentation. Most red wine studies have shown an overall slight decrease in wine colour density following MLF, but this is not influenced by the MLF inoculation regime. However, there can be differences in anthocyanin and pigmented polymer composition, with co-inoculation exhibiting the most distinct profile. Studies in Pinot Noir have shown some more significant loss in color following MLF. The color stability in Pinot noir wines following MLF can be influenced by several parameters and winemaking practices; onset and speed of MLF, time length of a planned MLF delay and the species of LAB used for MLF (Oenococcus oeni or Lactobacillus plantarum). Acetaldehyde is important in color formation and MLF can influence this process. MLF ENG Final

COLOUR AND TEXTURE MANAGEMENT

Recent research has given us a much better understanding of how yeast and phenolic compounds interact in red wine, enabling us to better characterize the biochemical and biophysical properties of yeast with unique wine-relevant characteristics. We have described the development of a specific yeast autolysate with unique wine sensory impacting properties. A yeast autolysate (MEX-WY1) was prepared from a wine yeast with distinctive characteristics. Studies using model grape must revealed the involvement of mannoproteins in the soluble fraction of the autolysate in the formation of stable complexes that contribute to colour stabilization and reduction in wine astringency. Winery trials demonstrated that adding the specific autolysate MEX-WY1 at the beginning of fermentation had a positive effect on wine sensory characteristics such as colour, mouthfeel, and fruitiness in red wine, especially Pinot Noir wines. Thus, the new specific autolysate constitutes a unique tool to improve colour and texture management in Pinot Noir. MEX-WY1 has been released as commercial product, OPTI-MUM RED™ OMR Color and Texture

Sauvignon Blanc

In an increasingly competitive market, optimizing the quality of wines, especially the sensory properties, is a major challenge for winemakers. Wine aroma is one of the principal attributes determining wine consumers’ preferences. The importance of nutrients such as nitrogen or lipids in alcoholic fermentation is well known in the wine industry. Indeed, to assure a complete fermentation with a regular kinetic, winemakers have to ensure that musts have adequate nutritional, physical, and chemical conditions for optimum yeast development. More recently, lipid content, temperature, as well as nitrogen and other micronutrients have been shown to have a great impact on a large number of flavour compounds biosynthesized by wine yeast during alcoholic fermentation. The interactions between nitrogen and other key nutrients such as lipids and vitamins and their influences on yeast viability and yeast fermentative capacities will be explain in the first part of this article. The second part will aim at demonstrating the importance of nutrients and micronutrients in yeast aroma metabolism as well as yeast’s ability to synthesize aromas and especially to reveal varietal aromas in Sauvignon Blanc winemaking. Stimula Sauvignon Blanc

Freshness

In the context of climate change, increased pH and alcohol content can result in heavier wines, while some consumers are moving towards a lighter, fresher style of wine. Beyond the notion of acidity, the sensory aspect must also be taken into account (fresh fruit aromas, vegetal notes, etc.). From veraison to bottling, each step can have an impact on the different layers of a wine’s freshness. This article aims to present recent results and tools related to fermentation management and the search for freshness in winemaking. Freshness ENG F

IONYSWF™

Adaptive evolution and crossing are powerful non-GMO approaches for selecting yeast strains with properties of interest, making it possible to go beyond classic phenotypes. In the case of IONYS™, these strategies made it possible to obtain a new yeast with a lower yield in terms of the conversion of sugars to ethanol and with overproduction of organic acids thanks to a redirection of carbon flows towards glycerol and the tricarboxylic acid cycle. Acidity Management