Resumen
The invention relates to the use of selective-differential media for stimulating the growth of yeast of the genera Brettanomyces/Dekkera, associated with the monitoring of the degradation of p-cumaric acid and the subsequent formation of 4-ethylphenol (smell defect) by means of instrumental analysis HPLC/PDA/ESI-MS, enabling the estimation and/or quantification of the existing microbial population and the potential vinylphenol-reductase enzymatic activity thereof by means of a statistic regression model. This technique is applicable to any stage of an oenology industry and other types of drinks industries.