One of the primary concerns of the enologist during winemaking is to ensure a steady and complete fermentation so that all of the sugars in the must are converted into alcohol. This should be done in order to avoid any unpleasant surprises that could arise, including a stuck fermentation or problems due to secondary metabolisms detrimental to the aroma and taste of the wine.

Nourished with micronutrients (the vitamins and minerals available in the must), sterols are responsible for maintaining the integrity of the yeast cell membrane and increasing its resistance to ethanol. The protection and nutrition of yeast are consecutive and complementary steps. Their benefits should be combined to ensure good alcoholic fermentation, with no problems with a stuck fermentation or secondary metabolisms compromising the quality of the wine.

In recent years, the use of selected yeasts in winemaking has become widespread, allowing greater control of the alcoholic fermentation and reducing the risk of unwanted sensory effects resulting from the growth and metabolism of contaminating indigenous yeast. However, a lack of nutrients in the fermentation medium, as is the case in very mature harvests (rich in sugars and polyphenols), harvests with Botrytis, highly clarified musts with low turbidity, and in the presence of inhibiting substances, can lead to slow or stuck fermentations.

At the end of the fermentation process, the yeast suffers a high degree of stress due to the high alcohol concentration and the difficulties in transporting residual sugars: the alcohol diffuses through the membrane and kills the cell. During the rehydration phase, protected yeast maintains a very high viability rate. Its membrane, rich in sterols and PUFA is able to withstand high concentrations of alcohol and prevent the alcohol from entering the cells. With this protection, the yeast can finish consuming all the sugars in the must. Healthy and stress-free yeast cells do not produce excessive amounts of undesirable compounds or volatile acidity. Protecting the yeast guarantees that the end of the fermentation is faster and safer. 

In conclusion, protecting the yeast cells during rehydration guarantees the following principal parameters:

• The reactivation of the internal metabolism thanks to the micronutrients. The yeast cells have more time to reinforce their cell membranes before being incorporated to the must.

• The consolidation of the external membrane, a vital organ for yeast cells, thanks to the micro-protectors

• Enhanced viability and cellular activity until the alcoholic fermentation process is complete

During fermentation, the protected yeast also indirectly assists in:

• Totally occupying the must with a good implantation, and restricting the activity of contaminating indigenous yeast

• Guaranteeing faster and safer fermentation

• Reducing the production of undesirable compounds, such as volatile acidity, H2S, etc.

The use of GO-FERM™ or GO-FERM PROTECT EVOLUTION™ during a stuck fermentation, or even with problem must, will help incorporate sterols and polyunsaturated fatty acids (for cell protection) along with vitamins and minerals to ensure yeast survival and maintain fermentation activity to completion. 

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