The biggest challenge for wine yeasts during alcoholic fermentation is surviving in a hostile environment – high osmotic pressure, acidic pH, alcohol produced as fermentation progresses, etc. – until there is no sugar left.
Wine yeasts have nutritional requirements as soon as they start to work. These nutrients maintain yeast vitality and optimum viability during alcoholic fermentation from start to finish, at the same time as ensuring the wine’s sensory quality. For over 15 years, part of Lallemand Oenology R&D has focused studying yeast physiology and nutritional requirements. Some nutrients, such as nitrogen, vitamins and trace elements, are needed to survive. From the very first stage – rehydration– they are proven to be essential requirements for the smooth alcoholic fermentation.
Lallemand Oenology yeast expertise and producer’s know-how have enabled processes and specific products issued from wine yeasts to be developed: inactivated yeasts, autolysates and cell envelopes. Each fermentation phase has specific requirements: protection, nutrition and detoxification. In 2001, Lallemand developed yeast protectants (yeast autolysates) introduced during rehydration. The patented Natstep™ process, specially designed in 2005 for rehydration, reinforces the yeast cell membrane through the actions of specific sterols. This protection increases the yeast’s capacity to resist alcohol and ensures a clear end to fermentation while limiting sensory deviations.
Wine yeasts must achieve maximum activity during alcoholic fermentation to prevent sluggish or stuck fermentation and sensory deviations. Appropriate nutrients have been developed to compensate for nutrient deficiencies in grape musts and help alcoholic fermentation run.
Since 2008, a new generation of wine complex nutrients containing 100% natural wine yeast derivates have been proposed by Lallemand Oenology to winemakers. They supplied well balanced yeast source nutrients to improve aroma precursors assimilation.