Expertise documents

An original and new specific inactivated yeast to improve the oxidative stability of white and rosé wines

In this paper we present research work carried out in collaboration with the University of Burgundy, which has highlighted the impact of a new specific inactivated yeast developed for the protection of musts and wines against oxidation. This results from the application of an optimized production process to a unique strain of Saccharomyces cerevisiae yeast to maximize the biosynthesis and accumulation of intracellular glutathione and other compounds of interest. Non-targeted metabolomic characterization has demonstrated the unique composition of the new inactivated yeast and its impact on wine compared with other inactivated yeasts (standard and high glutathione content inactivated yeast). In addition to its high content in reduced glutathione, the presence of other reducing peptides further increases the positive impact of this specific inactivated yeast on the oxidative stability of wine. Numerous application trials have been carried out, at pilot scale in particular, on white and rosé vinifications during the 2017 and 2018 vintages, to evaluate the impact of this inactivated yeast on wine quality when added before fermentation (after pressing, during clarification or in pre-fermentation cold storage). The results show that early treatment with the specific inactivated yeast allows for better preservation of aromatic compounds and color as well as increased radical-scavenging activity in wines up to bottling. Glutastar final eng

Management of malolactic fermentation to enhance red wine color and reduce the risk of Brettanomyces spoilage

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  

Alcoholic and malolactic fermentations: what impact on 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

Co-inoculation of wine bacteria during Wine fermentation: From new fad to a recognized practice

Co-inoculation is the practice of inoculating selected wine bacteria at the beginning of the winemaking process shortly after yeast inoculation. This technique has gained popularity not only because it assures a fast and complete malolactic fermentation, but also because there are numerous other advantages that are recognized by winemakers and wine professionals. In France and Spain for example, close to 50% of MLF is now conducted with co-inoculation. Co-inoculation plays a key role for a faster and more secure MLF process, an earlier wine stabilization, along with cost and energy saving. It limits the development of spoilage microorganisms and thus reduces off flavor compound production, ensuring wine quality. Co-Inoculation - Benefits -ENG

Inoculating with yeast to acidify

A non-Saccharomyces yeast, Laktia,  can naturally acidify white and red musts by converting a small amount of sugar into lactic acid at the start of alcoholic fermentation. This is a new way to acidify wine. The article is published with the permission of La Vigne TAP-ANG Levure