Wine yeast requires certain essential elements to transform must into wine: sugars, vitamins and minerals, some oxygen, and also very importantly, a sufficient concentration of Yeast Asssimilable Nitrogen. This type of nitrogen (YAN) is composed of amino acids, some small peptides and ammonium that can be used by yeast cells to not only complete fermentation, but also to fully develop the sensory profile of the wine. Many wine musts are deficient in nitrogen and the type of nutrient used and the timing of addition is crucial in the development of AF.
It has been shown that organic nutrients, which N-containing amino acids, peptides and proteins issued from auto-lysed yeast cells found in Fermaid O™ for example, and added at the beginning of fermentation and at 1/3 through the AF, are the best strategy for achieving complete and regular AF and maximizing the sensory potential of the wine.
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