Expertise documents

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CO-INOCULATION OF SELECTED WINE BACTERIA

This Winemaking Expert explores the ever increasing practice of co-inoculation. In France and Spain for example, close to 50% of MLF is now done via co-inoculation. The advantages are numerous, such as ensuring a faster more secure process and reducing time for the MLF. Co-inoculation is an important modulator in sensory development, and it helps limit the development of spoilage microorganisms and thus limits off flavor compound productions. For example, a wine bacteria like the Enoferm Beta can produce higher levels of diacetyl during sequential inoculation.  Co-inoculation on the other hand, will reduce the production of diacetyl and consequently reinforces the fruity character of white wines. Timing of inoculation, interaction with yeast, the presence of precursors that promote the production of aromatic molecules, pH and temperature conditions are all criteria that modulate aromatic expression in wines. Choosing a wine bacteria has become a parameter to take into consideration for developing a specific wine profile.

WE4 Australia

GLUTATHIONE AND ITS APPLICATION IN WINEMAKING

This edition of 'The Wine Expert' discusses how Glutathione -rich 'specific inactivated yeast' are natural winemaking tools.   OptiMUM White is a specific inactivated yeast rich in glutathione that was developed from a new optimized production process that enhances the reduced glutathione availability. OptiMUM White contains the highest level of true active and efficient form (reduced form) of GSH on the market. This product will have positive impact on color, wine thiols, wine esters and terpenes ; as well as an impact on the preservation of these aromatic compounds during aging.

WE3 V1 Australia

Balanced nutrition for a healthy alcoholic fermentation

Nitrogen is an essential nutrient for smooth alcoholic fermentation (AF). Numerous  studies have shown that nitrogen has a positive impact on the growth and fermentation activity of yeast (Bell et al. 1979, Ough and Lee 1981, Bezenger and Navarro 1987). Deficiencies in yeast-available nitrogen (YAN) in the must significantly increase the risk of sluggish or stuck fermentations because they can arrest protein synthesis in the yeast cells. We consider a must with an initial sugar level of about 200 g/L to be deficient when its YAN concentration is about 150 mg/L (Henschke and Jiranek 1993). A YAN deficiency in the must can also cause the yeast to increase the production of H2S (Henschke and Jiranek, 1991). This edition of the Winemaking update focuses on the impact of balanced nutrition on alcoholic fermentation.

Lallemand Winemaking Update #13 2010 - Balanced nutirtion

Specific Inactivated Yeast enriched in Glutathione

The utilization of specialty inactivated yeasts (SIY) in winemaking has gained popularity in recent years, and their uses are varied. For example, SIY can be used as protectors during yeast rehydration and as a nutrition tool during fermentation. As we understand more about the yeast cell constituents, the production process, the characterization of each yeast strain and their unique fractions, we can obtain very specialized inactivated yeasts to yield specific results under defined conditions. Such is the case for the inactivated yeasts that can trigger specific responses during fermentation due to their unique functionalities. This issue of the Winemaking update will focus on a new SIY designed for white and rosé wines.

Lallemand Winemaking Update #16 2011

Sculpting the aromatic profile of wine through diacetyl management

 In addition to carrying out the bio-deacidification of wine, malolactic (ML) bacteria influence aroma and flavour through various mechanisms, including the production of volatile grape- and yeast derived metabolites. In wine, one of those volatile compounds – diacetyl – has important stylistic implications. This diketone, also known as 2,3-butanedione, is associated with the “buttery” character of wine and is formed as an intermediate metabolite in the reductive decarboxylation of pyruvic acid to 2,3-butanediol.The formation and degradation of diacetyl is closely linked to the growth of such ML bacteria as Oenococcus oeni and the metabolism of sugar, malic acid and citric acid. Yeasts are also able to synthesize diacetyl during alcoholic fermentation (AF). However, most of this diacetyl is further metabolized to acetoin and 2,3-butanediol. This issue of Winemaking Update will review winemaking practices and the latest findings to help modulate diacetyl content in wine through malolactic fermentation (MLF).

Lallemand Winemaking Update #15 2012 - Diacetyl Management