Effect of nitrogen nutrition on grapes, fermentation and wine.

The management of vine nutrition has the potential to influence the composition of the berries and ultimately the composition of the wine, which in turn the quality and value of the product produced.

Nitrogen is an important macroelement with a key role in many biological functions and processes both in the vine and in fermentation microorganisms (yeasts and bacteria of malolactic fermentation).  Therefore, nitrogenous nutrition of the vine is expected to affect the concentration and composition of quality components of grapes. The composition of the grape is a determining factor in the composition of the must before fermentation. Thus, the concentration of nitrogen and the type of its compounds in the grape and therefore in the must significantly affect the quality of the wine produced.

Yeast growth, fermentation kinetics and metabolic processes of taste characteristics are significantly influenced by the state of nitrogen in the must, which when below the optimum amount, is regulated by adding nitrogen to the winery (Bisson 1991, Kunkee 1991, Henschke and Jiranek 1991, 1993). Furthermore, the role of yeasts in the development of aroma, taste and body of wines was perceived by the influence of nitrogen on yeast metabolism (Henschke and Jiranek 1993, Rapp and Versini 1996, Albers et al 1998, Hernandez-Orte et al 2005, Swiegers et al 2005).

However, although undoubtedly yeasts contribute to the composition of wine, there are many other components of the final wine that may be affected by the addition of nitrogen to the vineyard and/or winery, not directly related to fermentation.