During the process of alcoholic fermentation yeast, which is a complex living organism, is subject to various stressors: temperature, ethanol, pH, organic acids and others. In order to get a successful fermentation, yeast needs a balanced nutrient package which will maximize its potential to deliver high alcohol yields and a consistent congener profile.
The first nutrient yeast needs is nitrogen. Nitrogen is naturally present in all the feedstocks we use to produce spirits however, often the natural content is not sufficient or the yeast cannot uptake efficiently or at all. Yeast can uptake ammonium ions, small peptides and α-amino acids except proline. These three sources of nitrogen are collectively referred to as the YAN: Yeast Assimilable Nitrogen. The Free Amino Nitrogen (FAN) only includes α-amino acids and small peptides.
Our studies and other publications on this topic illustrate that a deficiency of nitrogen impacts the yeast growth and can cause slow and sluggish fermentation. In order to manage fermentation properly, it is recommended to use nitrogen in an inorganic (ammonium salts and not urea) or in an organic form. Organic nitrogen has been shown to be effective not only for ensuring efficient fermentation but also to develop and enhance the aromatic potential of the feedstock.
However, yeast is complex and needs other key nutrients such as minerals and vitamins which are necessary to support the enzymes involved in the biochemical reactions of the glycolysis and the fermentation.
To ensure that these other key minerals and vitamins are present we recommend to add complex nutrients. They can be added during the rehydration step using a dedicated nutrient and/or they can be added during the fermentation.
The last issue we have to consider is the feedstock used for the production of distilled spirits. There are two types of feedstocks that have to be managed differently: the first is sugar-based feedstocks (molasses, cane-juice, fruit, etc) and secondly starch-based feedstocks (corn, rye, wheat, barley, etc).
Considering all the different aspects of yeast nutritionnal requirements during the fermentation, Lallemand Distilling has developed a range of nutrients tailored to the various applications.
DistilaVite VM is used during the rehydration step on starch-based feedstocks and can also be used in fermentation.
Distilavite GN is a complex nutrient which supplements a broad range of essential minerals and vitamins. For this reason DistilaVite GN can be used both in sugar-based feedstocks and in grain mashes bith during rehydration and fermentation.
DistilaVite HY is a specific nutrient for grain-based feedstocks. It enables the gradual release of the amino-acids during the fermentation providing the yeast a consistent nutrition even at the end of the fermentation when stress is high.
To get more details on each product, please look at the dedicated technical data sheet or contact your local technical representative who will be happy to assist you.