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.
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.
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.
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.