Expertise documents

TECHNICAL ARTICLE – GUARDIA

Active bio-protection in red wines with Metschnikowia pulcherrima

ONE OF THE NON-SACCHAROMYCES YEASTS STUDIED IS METSCHNIKOWIA PULCHERRIMA. THIS ARTICLE WILL FOCUS ON THE ANTAGONISTIC ACTIVITY OF A SPECIFIC STRAIN, M. PULCHERRIMA LEVEL2 GUARDIA™, ON OTHER WINE YEAST SPECIES FOR BIO PROTECTION APPLICATIONS. BY Amandine Deroite To read more please click on the link below:  GUARDIA Active bio protection article for red wines November 2021 (002)

TECHNICAL ARTICLE

What's so Special about Specialty Wine Yeast?

For more than 50 years now, selected wine yeasts have been used by winemakers successfully in active dry yeast form. It has been longer than that, since Pasteur discovered that Saccharomyces cerevisiae was responsible for alcoholic fermentation, that winemakers have intuitively selected the best wine yeasts. Now, with dedicated selection program, winemakers have access to the best of the best in terms of wine yeasts. Why is there so many available and what sets them apart from one another? These are why, selected wine yeast are special..... To read more, click on the link below: Whats so special about specialty wine yeast

Micro agglomeration & bioavailability of sterols – the revolutionary wine yeast protector

Faster Yeast Rehydration   🍷The impact on the fermentation process and final wine quality are now greater due to climate change, with higher sugar/ethanol contents, higher pH’s, off-flavours caused by yeast stress, sluggish or stuck fermentations and higher microbial contaminants. It is now crucial to select wine yeast in dry form (ADY) in the optimal physiological state to have healthy and active populations capable of completing alcoholic fermentation. 🔬Over the last 20 years, scientific information on yeast nutrition management in winemaking has significantly increased. The role of key nutrients, such as nitrogen sources, oxygen and micronutrients like vitamins and minerals, have been the subject of research and publications,5,1,7 showing their impact on fermentative activity and wine sensory profile. 🔬In parallel, specific research has focused on how sterols influence yeast’s physiological state and metabolism and how it was directly correlated with a secure end of fermentation.7,4,6 It has been shown that using specific yeast autolysates rich in sterols during the rehydration step of the ADY increases the fermentation activity and vitality during fermentation, particularly in the last part, when alcohol levels become toxic for the yeasts. This is related to improving yeast cell stress resistance correlated with better membrane integrity. 🍷ADY rehydrated with protectors (Go-Ferm Protect™/Go-Ferm Protect Evolution™) maintains their viability and vitality until the end of fermentation, decreasing the risk of stuck or sluggish fermentations, avoiding undesirable aroma production, and resulting in an increase of the aroma compound synthesis by the yeast with the protectors. The incorporation of the sterols in the ADY rehydrated with protector leads to an increase in their membrane lipid composition and healthier cell membrane. The protector effect is notable at different temperatures, high potential alcohol, lack of oxygen or low turbidity in white and rosés. This article was published in the November issue of the WineLand magazine. Read the full article at the link below: Micro agglomeration bioavailability of sterols  

The fructophilic yeast to rescue stuck fermentations

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 non-fermentative yeast, the new LEVEL2 INITIA

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