Uvaferm 43

The ability of wine yeast to consume fructose.

Article written by Ann Dumont, Céline Raynal, Françoise Raginel & Anne Ortiz-Julien Research has shown how certain fermentation conditions, such as nutritional deficiencies, high initial levels of sugar, and the presence of inhibiting compounds, can lead to fermentation problems. Under oenological conditions, the main sugars fermentable by Saccharomyces cerevisiae are glucose and fructose. Both of these hexoses are generally present in musts in equivalent quantities, but the proportions may vary in some musts. S. cerevisiae prefers to consume glucose, which ex -plains why, when fermentations become stuck, the remaining sugar is mainly fructose. The frequency of stuck fermentations showing residual fructose raises the question of the ability of yeast to consume this hexose.  The kinetics of sugar utilization by S. cerevisiae during fermentation is largely driven by sugar transport, and glucose is typically consumed at a faster rate than fructose. In sluggish fermentations, the maximal rate of fermentation is reduced after most of the glucose is consumed, and fermentation can become stuck with a significant con-centration of fructose remaining. Please click on the link below for an in-depth explanation of this topic. Ability of Wine Yeast to Consume Fructose

A yeast that reduces sulphites in wines

Implemented, for the first time on a large scale, during the recent northern hemisphere harvest, LEVEL2 INITIA, a non-fermentative yeast which consumes oxygen, has proved to be very interesting in reducing sulphites. For the vinification of wines without sulphites or with reduced doses sulphites, winegrowers have a new weapon: LEVEL2 INITIA. This non - Saccharomyces yeast , selected by Lallemand in partnership with the Institut Français de la Vigne et du Vin (IFV) and distributed by the Institut Coopératif du Vin (ICV), showed promising results during the last harvest. To read the French article about the winemaker's experiences please click on the link below (remember to translate it to English when asked): https://www.vitisphere.com/actualite-95790-une-levure-reduisant-le-sulfitage-des-vins.html

Also a yeast for bioprotection.

The pre-fermentation phase during the vinification of white and rosé wines significantly increases the quality of the wines, but also carries the risk of oxidation and the development of spoilage microorganisms. These risks may result in loss of quality. In recent years, changes in winemaking practices, regulations and consumer demand have resulted in a significant decrease in the use of sulphites. Increasingly, winemakers are considering bioprotection of musts using non-Saccharomyces yeast. Each species of these yeast has its own specific contribution and differences between strains can also be observed within the same species. For more information on this new exciting product please click on the link below: Level2 Initia Article Wineland December 2021  

UNDER INVESTIGATION NO4

The use of selected wine yeast in dry form dates to the mid-1960’s (Kraus et al, 1983). Gradually, this practice has been one of the most important innovation in winemaking.  It allowed winemakers reliability and security during alcoholic fermentation (AF), as well as a tremendous choice of different yeasts, without the concern related to managing a often delicate and difficult spontaneous AF, with all the risk related. Yeast production is a true expertise, one that relies on a strong understanding of yeast metabolism, microbiology and process. The selected wine yeast used by winemakers must be in optimal shape. In order to obtain optimal state, specific feeding regime during its growth and development, tailored to each specific wine yeast, as they are all different, is learned and optimized by true science and years of experience and research. This Under Investigation will showcase how selected wine yeast production is conducted and why it benefits winemakers.

Benefit of ADY - ENG

Wine Yeast Under Investigation #3

The initial microbial population present in grape must is very diverse. During the early stages of alcoholic fermentation, Saccharomyces cerevisiae is not the dominant specie and other species (non-Saccharomyces) are present. Non-Saccharomyces yeasts are part of the must microflora and represent an important reservoir of the wine sensory potential. While some are detrimental to sensory quality, others have the potential to add to wine complexity or bring about a real benefit with the right selected Saccharomyces yeast. Three species are presented: Torulaspora delbrueckii, Lachancea thermotolerans and two different strains of Metschnikowia pulcherrima. Read more at the link below: UI Non-Saccharomyces - ENG no 3

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