The progression of alcoholic fermentation is conditioned by the ability of the yeasts to carry out their vital functions comfortably. A fundamental condition, both in the development of yeast populations and in the full expression of the characteristics that distinguish each yeast strain, is the correct balance between sugars and nitrogenous substances.
The nitrogen present in grapes and musts that is accessible to yeasts is expressed as Easily Assimilable Nitrogen or AFN. This nitrogen content consists of ammonium and assimilable amino acids (all except proline). The nutritional value of amino acids is much higher than that of ammonium, so that amino acids, and particularly some of them, such as arginine, play a major role as resistance nitrogen at the end of alcoholic fermentation. AGROVIN proposes nitrogen recipes with a high proportion of assimilable nitrogen in the form of amino acids.
Más información sobre Nutrients
Types of nutrients:
– Organic: these are nutrients that provide assimilable nitrogen exclusively in the form of amino acids. Their exclusive use at the beginning of fermentation avoids excess cell multiplication, lower production of hydrogen sulfide, greater aromatic intensity and increased varietal character.
– Complexes: broad spectrum complex nutrients with a balanced formulation. The combined nutrients provide, in addition to ammonium salts, amino acids, growth factors (vitamins, minerals) and survival factors (sterols and long-chain fatty acids). They help to compensate the nutritional imbalances of the must, avoiding the increase of volatile acidity and the thermal increase of the must or mash.
– Inorganic: they only provide inorganic nitrogen in the form of ammonium salts.